After destroying Mass Effect 2 for the first time, I decided I would finish off the remaining achievements and insanity difficulty with a continuation from the same character. (For reference, my mass effect 1 soldier - now 26 going into insanity) 
 
I forsee this difficulty taking a while to wade through, and I imagine some parts will be quite painful. 
 
My question to you: 
 
Do you think enemies scale in a more beastly way when you import for the second round insanity. 
 
What moves would you consider vital among the list you receive for the second playthrough as a soldier. 
  
Feed me. 

-Bacon

Warp Ammo.
Warp Ammo.
Maybe Reave.
No wait, Warp Ammo.
 
I've only finished Freedom's Progress on Insanity but all the Loki mech things now have a layer of armor before you can get to their health and do alot more damage, as expected.

I just got mordin with my Soldier on Insanity, level 30, and even with the revenant machine gun and inferno ammo, just the damn vorcha are tough as hell. I picked fortification as my bonus power, thinking more defense would be good, but now I'm thinking I should have tried something else. Thing is, I don't see anything else that would help me survive any better. It's truly hellish. Inferno ammo is your friend, though.

Barrier is a must. When you get to the max barrier level, go to Heavy Barrier, there is no point in the duration increase. 
Adrenaline rush is great, as it allows you to jump out of cover and take some shots to the head, and then jump back down. 
 
For weapons, I suggest you have the HW - Cain. Sure, the Cain is the most pain in the ass weapon to use, but it saved my ass a lot when having to fight against the super powerful Patrasomethingorother enemies (the husks with a bunch of heads that like to cast barrier all the time) 
If you are not a fan of Barrier, you can use Fortify (Grunts Ability). 
 
Also, be prepared to switch ammo often, by often I mean adapt. If Enemies have shields, use appropriate weapons, then switch to incendiary for armor, and squad cry ammo is great too; it allows you to freeze hoards of enemies and break them.

I'm going through Insanity right now with a Soldier, as well.  I'm finding that using Mordin and Miranda is best for my play style.  I like having Incinerate, Overload, and Warp... along with Disruptor and Incinerate Squad Ammo types. 
 
For my chosen power, I've been using Grunt's Fortification.  Warp Ammo could probably kickass too, but can't have everything, and Barriers seem to not be as much as a problem as Sheilds/Armor.  This may change later on.  I think retraining to Warp Ammo from Fortification might help mostly on the Collector's Ship stages. 
 
Unfortunately, I think what I'm gunna do today is maybe even start Insanity over again with a new character (ME1 import), as to scale everything back to like Level 5.  Still deciding about this, but maybe I'll wait until I get 2 more Levels for the Level 30 Achievement first, then start over. 

Wow. I was considering making my second playthrough on Insanity with a new character, but it sound like it's only possible with the powers that come with a high-level character. Thoughts?

I just started an insanity run and find it a bit annoying, tbh.  All the enemies just have shields.  That's all I can tell.  So I just sit in cover forever trying to whittle down their shields and health.  The overload and all those powers do little damage even tho it is specifically suppose to damage shields.  I run out of assault rifle ammo on pretty much every encounter.

I started this one with barrier...so hard :)

" Wow. I was considering making my second playthrough on Insanity with a new character, but it sound like it's only possible with the powers that come with a high-level character. Thoughts? "

Doing Infiltrator right now, with Bonus Power Neural Shock, though it's still at rank 1, and not that great for what I'm doing. I'm still a fan of Inferno Grenade, but I don't think you can pick that even on new game+ until you help Zaeed.
 
Hanging back sniping with Tactical Cloak isn't so bad on Insanity, I'd imagine sentinel with tech armor to be easier as well with less overall deaths. Vanguard seems like it'd be tough, as charging into a group of enemies doesn't seem like the best choice, especially since all your abilities are on cooldown when you do.

" Wow. I was considering making my second playthrough on Insanity with a new character, but it sound like it's only possible with the powers that come with a high-level character. Thoughts? "

Good to know Insanity is a stiff challenge!  I'm not even touching this difficulty level until I can carry over my Shepard from Playthrough #1...  but by then I'll want to replay with a different class so we'll see.

" I played with this last night and I think if I remember it still let me pick a new power!  I'm gunna check this again as soon as I get home, but this looks like an awesome loop-hole.  I think all you have to do is just beat ME2, then if you do another ME1 import, it still lets you pick a power like Fortification.   Forgive me if I'm wrong, but I swear this happened to me last night, when I was up at 2:30am and super tired :p  "

" Everything being scaled back would probably help. You can pick one of the loyalty powers when you start a new game so that isn't not a super huge deal "

" @Mariek430 said:

" Everything being scaled back would probably help. You can pick one of the loyalty powers when you start a new game so that isn't not a super huge deal "

Excellent. Thanks! "

Got to the Praetorian battle on Horizon a minute ago, and wow that was brutal. Husks with Armor rushing you from both sides, in addition to the Scions. So far this is the hardest part I've come across, I really hope it doesn't get worse...  Went in with 2 medi-gels and tried to conserve them, but ended up with only me and Grunt for the Praetorian. Which I came close to dying numerous times. Thank you tactical cloak!

I am playing through on insanity as a sentinel.  The pace of the game certainly slows down significantly (especially from the casual or medium level) because cover becomes an absolute necessity.  Tech armor is necessary for me, because I tend to stick my neck out too much.  The bonus power I chose was Reave, which is fast casting and super effective versus Vorcha (no regen).  Also- I believe reave is effective vs. both barriers and armor.  This means that, as a sentinel who is accompanied by Miranda/Mordin, there is plenty of armor busting (warp, reave, incinerate) and plenty of shield busting (dual overload) and you also get some squad benefits from Miranda.  
 
I think that my second additional power (do I get one?) was going to be warp ammo, and my second gun was going to be the AR... but who knows.  
 
this is certainly giving me quite a challenge- the archangel level was pretty tough.

Infiltrator for the win, basically.

I went through the game my first playthrough on insanity as an adept, and I can think of about 4 separate spots that sucked a whole lot of ass. Other than that, however, you should have no problems at all so long as you play it conservatively. Don't stay out of cover too long, don't try to squeeze off that 'one extra shot' because it will get you killed. I can't count the number of times that I thought to myself "i'll just throw out this warp because it just came off cooldown even though I only have a negligible amount of health left" and proceeded to get destroyed the second I popped out of cover. I wound up having to get fortify as my teammate ability because I was so squishy that I couldn't run from cover to cover without dying most of the time. 
 
I brought Mordin and Miranda with me for about 90 percent of the game because the three of us combined can take out armor, barriers, and shields almost instantly. And once they have just health left, just spam throw while the teammates finish them off. If you're looking for a good challenge, I'd say go through as an adept. It's a lot of fun.  Frustrating at times.... but fun.

Hold on. You're able to get the Insanity achievement on a second playthrough with an existing ME2 character? Really, I swear I read you're unable to. 

" I went through the game my first playthrough on insanity as an adept, and I can think of about 4 separate spots that sucked a whole lot of ass. Other than that, however, you should have no problems at all so long as you play it conservatively. Don't stay out of cover too long, don't try to squeeze off that 'one extra shot' because it will get you killed. I can't count the number of times that I thought to myself "i'll just throw out this warp because it just came off cooldown even though I only have a negligible amount of health left" and proceeded to get destroyed the second I popped out of cover. I wound up having to get fortify as my teammate ability because I was so squishy that I couldn't run from cover to cover without dying most of the time.   I brought Mordin and Miranda with me for about 90 percent of the game because the three of us combined can take out armor, barriers, and shields almost instantly. And once they have just health left, just spam throw while the teammates finish them off. If you're looking for a good challenge, I'd say go through as an adept. It's a lot of fun.  Frustrating at times.... but fun. "

i've just completed horizon, sentinel level 16 on insane. It's hard as nails but not impossible. Hardest problem is ammo and medigel. I keep finding myself facing 6 enemies with no medigel, both my comrades down and completely out of ammo. 
 
Extremely annoying.

I started a second playthrough on Insanity w/ my lvl 28 Vanguard. Its been pretty rough, honestly. I don't have a lot of powers that are good against dudes w/ shields/armor/barrier so I've been relying on Mordin/Miranda to soften guys up. Unfortunately they get killed pretty easily. I've recruited about half the squad now, but I know that fight on Horizon w/ the two Scions and the bigger thing is going to be terrible for me. 
 
I picked Barrier for my special skill, its pretty much saved my ass the entire duration of the Insanity playthrough. Charge/Pull/Shockwave are all pretty useless until you get shields/armor down which takes a lot of whittling.. *sigh*

Would you say starting insanity with a new character, or with a new game+ character from your previous ME2 playthrough is the easiest?
 
I thought, since the enemies scale, maybe it would be easier if you started from level 1?

I thought i would try Insanity with my adept from my first playthrough....yea i gave that up, its just absolutely infuriating to try and wear down every single enemy's armor/barrier and then killing them, while the time it takes me to peak out of cover to cast warp costs me all my shields and 75% of my health. Ill be trying insanity using a different class cause Adept just doesnt seem well suited to handling everything thats going on, especially since practically all biotic powers except warp are useless until armor/shield/barrier is down but by then its not practical to use pull or singularity or whatnot on a vulnerable enemy when you can focus fire them down in a second anyway.

Yeah I got through it. Honestly I think the hardest part was the Scions. Those shockwaves just wreck you. I ended up jumping on a flatbed truck and hiding behind some boxes and shooting down at the Scions until they finally died. Apparently they couldn't hit me up there. It was kind of a cheap victory but after dying 15 times I was ready to take what I could get.

My thoughts on any difficulty setting in any game that isn't the Default one is that challenging is considerably different from masochistic.

I started a Hardcore playthrough with a Level 25 character... f#*k me!.. Can't imagine someone beating it fresh on a first go with no upgrades... even the "Collectors human zombies" take about 5-6 shots to take down with an assault rifle, you learn really fast though.  Screw insanity!.. It'd be a waste of time if you haven't already beaten it on hardcore because every stage just takes alot of knuckling down and working on the enemy slowly.

Your teammates' AI are shit.  They need to be improved.

I played through my first game on Insanity, and it wasn't too hard once you get used to the cover necessity. Also, my Infiltrator Cloak was a must

Finished Insanity. Honestly the hardest part was definitely the Horizon mission. Once I got passed that I found and researched enough upgrades that gave me an edge in the combat and I died a lot less. The end of the Derelict Reaper w/ all those stupid husks was annoying, but they only killed me a couple times. 
 
I still maintain that Vanguard is a shitty class for Insanity. I basically used Barrier and Incendiary Ammo the whole time. And Pull for Husks. My squad was Mordin/Miranda for their biotics.

I can imagine the Scion and Husk bit being the hardest, though I'm not through the entire game so I don't know about the end. Playing on Veteran now, just got my team and made most of them loyal. So when you beat it do you get to pick one of their loyal powers or something? I might start a new character for insanity, I think the scaling it back might help.

I was planning on do an insanity run with my adept but i went hardcore and see how that will work out. What should be alt power be? I have reave and it works well but I just keep having to warp my enemies.

I think veteran is challenging enough at points. And seeing as there's hardcore sitting between that and insanity... I honestly can't see myself getting that achievement.

Insanity isn't too bad.  Boring, at times, as you're sitting behind cover waiting for your health to regen 80% of combat, but otherwise not terrible.  I think it scales up your crew's shields and health to deal with the amplified damage and accuracy of your enemies, so they don't just die right off the bat every fight as long as they find their way to cover.  Warp ammo and Heavy Warp are the two most useful abilities, while Assassination Cloak is somewhere up there if you happen to be an infiltrator like I was.  The worst part of the game is the collectors, as it takes a mountain of ammunition to take out one of the controlled flaming collectors, and every time you take one out, one of its friends will get controlled right afterwards.  I probably died 25 times over my Insanity run but I only felt like the game was being super cheesy about 5 of those times.

I had no problem with Horizon on insanity. What kills me are the Blue Sun heavies and the Blood Pact flamethrower dbags. I wish my team mates were at least somewhat useful. I feel like I'm soloing the game.

After two hours of Insanity as level 30 soldier I have given up and lowered  the difficulty one step, it just wasn't much fun to have every enemy be a bullet sponge and then just sitting in cover waiting for the shield to recharge all the time to then make the next short attack. The most annoying part was having a Krogan run at you, as there wasn't much you could do against it aside from just firing away and hoping that he dies before you have to reload. The game wasn't what I would call especially hard on insanity, it was just really tedious. What is especially annoying with Insanity is that all short-range weapons end up being basically useless, as getting close to an enemy means certain death, so you just try to keep at much distance between you and the enemy and hope that the ammo doesn't run out.

" Warp Ammo. Warp Ammo. Maybe Reave. No wait, Warp Ammo.  I've only finished Freedom's Progress on Insanity but all the Loki mech things now have a layer of armor before you can get to their health and do alot more damage, as expected. "

ME2 Insanity = ACTUAL INSANITY... in my case at least. Some parts are very, very difficult and I feel they shouldn't. Most of the Collector based missions are the worst. Fighting Scions and Harbinger at the same time while fighting other drone Collector's is a bitch. Krogans are asses, husks are asses, and geth primes are asses. That's too much ass.  
 
I'm a ME2 imported soldier and I had concussive shot but I decided to drop it for inferno ammo. That was one of the best choices for me on insanity. Concussive shot is absolutely worthless because everything has some other bar protecting their health. Inferno ammo is a must as a soldier on insanity because almost all organic baddies have armor and their standard health bar. Inferno rips through that and makes them stumble and flinch.  
 
What the insanity becomes is an ammo type and adrenaline game. I'm always switching between ammo types, switching guns and using adrenaline so I could kill the baddies ASAP. Like I said before, inferno is great, but warp and disruptor are also important. Many times there will be a baddie (or baddies) who is/are using barriers and that's why Warp ammo becomes useful. It's essentially inferno ammo (stats wise) and it inflicts a lot of damage on barriers too. When ever I face I synthetic baddie I use disruptor ammo for pretty much standard reasons.  
 
Finally it's important to have squadmates who can help break through those damage soaking bars. Initially I had Samara and Miranda. They died way too often so I went with Garrus and Thane and it's much better. The reason why I had Miranda was for her warp and overload. Garrus and Thane split the weight, hence they're able to soak in more fire. Thane also has throw so that's useful when facing groups of husks.

I think adding armor to the husks was a real dick move.  But I was finally able beat it (and get my S-rank).  Never again though, I'll just stick to Veteran from now on.

" If you are not a fan of Barrier, you can use Fortify (Grunts Ability).  Also, be prepared to switch ammo often, by often I mean adapt. If Enemies have shields, use appropriate weapons, then switch to incendiary for armor, and squad cry ammo is great too; it allows you to freeze hoards of enemies and break them. "

I'm working my way through it as an infiltrator. Early on it was really difficult, but since I got the Widow sniper rifle things have been much simpler. I would also advise starting a new character as opposed to importing. The enemies scale to your level, but you don't keep any of your upgrades from your previous play through. Its pretty much the equivalent of going to the end of the game without upgrading anything.

Max Warp Ammo, get the Squad one. Max Adrenamine Rush, the one that reduces damage. Max Squad Disrupter Ammo. Get Shock Trooper for more health.
Get Miranda with maxed Overload and Warp. The other party member is interchangeable. Good choices are Mordin (Incinerate), Grunt (a freaking tank. Will help if enemies get close.) and Tali (drone can distract enemies).
 
Spam Adrenaline like no tomorrow. You should almost never pop out of cover without adrenaline. Get armor that boost health.

Im yet to try warp ammo on the enemies because I've not bothered selecting it yet but my only problem so far is Krogans and Mechs, mostly Mechs though.

If you want challenging, I think Hardcore scratches that itch just fine.  Insanity approaches masochistic.  It can be very demoralizing fighting a huge group of guys for 15 minutes only to die at the very end. Those 15 minute fights are not uncommon since even the lowliest bum is decked out in full armor and shields.  I imagine Sentinels having the easiest time dealing with Insanity.