Man I have to say that the Blackstorm Projector is fucked up good. Like, I'm actually glad I got this from Gamestop because the gun will mow down hordes of enemies even on insanity. I just got through the first part on Horizon where you come across the two Scions and all the husks with 4 Blackstorm shots. Also, while I was playing on my Insanity with my Adept, I equipped my Shepard with all armor that gives increases to Powers, by a certain percent. In the end all my equipment came to around a 20% increase in damage - extremely impressive. One of the biggest factors in this was the Dr. Pepper Biotic Visor DLC, which increases biotic powers by 5%. I know it's not much when you stack them all together it makes a hell of a difference. The Collector Assault Rifle is amazing as well. 
 
Am I the only one to feel grateful for all this free stuff which actually helps during the game? I see a lot of people bashing all the DLC for the game but IMO it's great so far. 
 
Right now I'm playing a Vanguard with the Cerberus Armor and Eviscerator Shotgun. It seems they made those two items specifically for Vanguards and Soldiers, which was perfect timing for me :D

I understand why people might bash it, since you're given a game and you'd think it'd all work without having to download anything.  I know why they do it, and I guess even the free stuff with the regular versions of the game help as an anti-pirating measure to at least get people to pay to hook up to the Cerberus Network.
 
As long as the base game isn't busted or deliberately worse somehow without the DLC, though, I don't care too much.  I'd probably not get any non-story or non-character DLC just as a challenge to myself, but that remains to be seen.

Never used the Collector armour before I got the Cerberus suit, but the shotgun has helped because it feels like it actually works, the suit gives me more of an edge I feel, Zaeed helps because he's a raw fighter/soldier class and the collector's assault rifle helps on insanity when my Vindicator just doesn't mow down hard enough.

The Eviscerator Shotgun is awesome with a Vanguard. The Insicor Rifle, which I got during that Xbox.com screwup, is cool, but can't really compare to the Widow late in the game. Same with the Collector Rifle and the Revenant. Got the the Dr Pepper DLC thanks to that srewup, too, and I've been using the Sentry Interface, mostly due to it looking awesome and not obstructing my face, as well as that bonus shield power.

 
Sadly, haven't used the Blackstorm much. Haven't used the armors either, thanks to no helmet toggle. I've been working up to an Insanity playythough, so I'll probably use all the armors during that. Waiting for Kasumi and the Hammerhead before that, though.

Collector Assault Rifle was pretty solid for me in my Sentinel Insanity run, and I also used the Collector Chitin Armor the whole time for the crazy health increases. I didn't use the Blackstorm Projector much because I prefer the simplicity of the Particle Beam.

@xyzygy:
I'm going to guess yes. After her and the Hammerhead, though, I'd say that anymore big expansions will probably be paid. 

 
Never know, though, I guess. It'd be nice if she were free.

 The Blackstorm is the singularity gun right?  Yeah, that thing is really powerful.  It helped me in one or two spots on insanity.  Specifically, I remember in the Grunt recruitment mission, the final fight with Judeau (I know thats not her name, but it was something like that) - used four shots of the singularity gun to take her out immediately - while she's alive krogans will keep spawning from the clone tanks.
 
I hope Kasumi really does get released..  and I hope the Hammerhead doesn't suck.

I felt that the weapons heavily outweighed the armour for use factor. I used the collectors rifle all the time for my supporting cast but didn't really use the singularity gun, the particle beam weapon works just fine for what I used it for. 
 
For the most part I just bought the upgrades for my own armour and say to hell with the helmet and did good enough with them. If you like the perks of the armour and can stand not being able to see yourself talk then I say go with the armour but the game does allow your armour to upgrade enough to really not have to wear it all the time.

I wore the Blood Dragon Armor almost the entire time through my first playthrough. It certainly helped out. Haven't touched the new shotgun though.

I don't really use any of that in game stuff so I guess not. But that's not to say it wouldn't if I did choose to use it.

I like the recon hood from the dr pepper promotional but that's about it.  Oh, the eviscerator was nice too until I got the claymore.
 
I general though the armors are awful because they aren't modular and the N7 armor lets you actually wear what benefits you or what you prefer.  The weapons I could take or leave, eviscerator is nice but more of a sidegrade from the tier 2 shotgun... the singularity weapon seems ok but nothing beats the CAIN For sheer awesome or the geth heavy beam weapon for versatility on insanity.

There's a Dr. Pepper exclusive weapon??

" There's a Dr. Pepper exclusive weapon?? "

I actually greatly prefer the Scimitar for the Vanguard over any other shotgun. You get the range with the Eviscerator, sure, but you only have three shots before you need to reload, whereas the Scimitar is comparable, if not greater, in power, and allots you eight shots per magazine. The Scimitar is a Vanguard's best friend when in the midst of a Collector swarm. 
 
I do like all of the DLC outfits. I'm one of the lucky few who snagged all the equipment when it leaked the night before Mass Effect's release. I'm a big fan of the Dragon Age armor, but the Cerberus armor is definitely the one best suited for Vanguards. Although I'd say, by the end of the game, custom armor pieces you buy along the way end up being superior. Plus, I kind of hate not being able to see Shepard speak. 
 
I'm on the fence about the Blackstorm Projector. I suppose it's alright, but in the time it takes to charge up, shoot out a bolt, and soften the defenses of any noteworthy enemy, I could have charged in and wiped out a platoon. Save, probably, your Horizon situation with the Scions. Even then, though, I'd rather charge in and play bullfighter with their AoE attacks than dance around them at long range and hope their Shockwave doesn't land a shot.

"  The Blackstorm is the singularity gun right?  Yeah, that thing is really powerful.  It helped me in one or two spots on insanity.  Specifically, I remember in the Grunt recruitment mission, the final fight with Judeau (I know thats not her name, but it was something like that) - used four shots of the singularity gun to take her out immediately - while she's alive krogans will keep spawning from the clone tanks.  I hope Kasumi really does get released..  and I hope the Hammerhead doesn't suck. "

I have the DDE with the pre-order bonus DLC and I haven't touched any of it. The armours look butt ugly and obscure Shepard's face and the guns are just weak.
 
I've completed 2 Insanity playthroughs just fine.