While I love both Mass Effect's, I can't help but feel that ME1's instant gratification of redeemed experience points was better than ME2's chapter/quest based experience point distribution system.  Basically, if you shot an enemy in ME1, experience points would pop up on screen, whereas in ME2, once you completed a chapter or quest, THEN you would get a set amount of experience points regardless.  Maybe it's OCD from years and years of playing RPG's but I like knowing that when I have defeated an enemy, particularly a difficult one, that the reward will be reaped right after.
 
Personally, I would like to see Bioware fuse the two of them together, and reward the players that use biotics or shoot in an effective manner, but also reward by chapter.
 
What do you like more?

Well basically since you have to find or purchase attribute boosts using money you found or received at the end of a mission, you stats as it were had entirely too much dependance on you playing through those godawful hacking minigames you have to do to earn most of your money instead of your proficiency. I know gamers don't like things that call attention to how poorly they played through a level but getting money bonuses from completing a mission quickly or completing a mission with a certain level of accuracy should give you a boost in the money you get. And probing is awful. If it exists at all it should be limited to shooting a single probe at a planet and grabbing up the entirety of its resources, and maybe there are upgrades to make it more affective but even then its never a completely tedious awful diversion. Basically I shouldn't have to play through that awful hacking game or that tedious probing game to get the next upgrade I need. Its not fun unless you're a masochist. 
I do not, however, want anything resembling grinding that can be exploited. I do not want  a 'cha ching' and "$20 earned" to appear after killing every enemy. The game is already mindnumbingly easy even though they make sure you can't purchase every upgrade, bringing back grinding is beyond redundant.

Hacking should, if anything, be a passive skill. So if, like me, you can't stand doing it, upgrade your hacking passive skill and you complete it automatically. They could have different levels of 'encryption' basically associated with hacking so if your passive hacking level is 3 you only have to play through hacking games with level 4+ encryption. Or make it completely passive and if your level isn't high enough you simply can't get it, basically making it identical to lockpicking.

Back to topic: Does Borderlands have the right idea for the delivery of experience gained, or should it be all at once at the end of the chapter?

i'd say back to 1 
and also weapons back to 1

I'd like to see a mix of the two.
 
Give me experience points for every kill, every hack, every thing I do, but then award me a larger experience dump at the end of a mission for completing the quest. Obviously I want to be rewarded for finishing a mission (main story or side quest regardless), but reward me for actually killing all the enemies, cause sometimes I'll bypass enemies I don't want to fight (the Mako segment on Feros comes to mind). You could also give me more xp for better kills (head shots, biotic combos, etc.). This way every part of a mission, right down to the weakest mech kill, feels rewarding and satisfying.
 
@kishan6 said:

" i'd say back to 1 and also weapons back to 1 "

 Do I really need 15 versions of the same kind of Assault Rifle in my backpack when I already have the next  level of that rifle with me equipped?

" @MystDragon3k said:

 Do I really need 15 versions of the same kind of Assault Rifle in my backpack when I already have the next  level of that rifle with me equipped?

Yes You do "

I find that experience points popping up on screen is much more satisfying than having a number shown to me after completing a mission.

I felt like to often in ME1 you were forced to go the more shoot everyone route. Talking your way out of situations wouldn't garner near the amount of experience. 
In ME2 though I felt free to do whatever I wanted knowing the experience at the end would be about the same.

" I felt like to often in ME1 you were forced to go the more shoot everyone route. Talking your way out of situations wouldn't garner near the amount of experience.  In ME2 though I felt free to do whatever I wanted knowing the experience at the end would be about the same. "

I think they should take the RPG parts of the first game and the presentation/characterizations of the second game and make like, a super game. It would be the best ever.

" @Slax said:

" I felt like to often in ME1 you were forced to go the more shoot everyone route. Talking your way out of situations wouldn't garner near the amount of experience.  In ME2 though I felt free to do whatever I wanted knowing the experience at the end would be about the same. "

They could give you experience every time you manage to talk your way out of a situation.  "

yep, I like how ME1 had the xp system.

ME1's XP system has saved me from certain death a few times because I ranked up in mission. ME2's XP system was annoying because on Insanity I spend hours on one mission and then rank up and get the perk that would have helped me halve the time it took to beat that mission.

Me2 just streamlined the RPG elements, and it made it easier. I liked not having 20 or so different rifles with minimal differences, just give me the one that will drop people the quickest. 
 
XP Point system... i didn't care b/c I'm just too much into the story to worry about numbers and stats. If anything being able to assign what Biotic powers you want from  the beginning so you're not stuck with a power you dont want (When has Charge ever worked?)

I preferred the upgrading stats system they had in ME1. If you had a single point you could put it wherever you wanted. Not like in ME2 where if you only had one point you have to wait until you have more to progress to the next level. ME1 had a better sense of progression, every little bit made me feel I was getting a little bit stronger, unlike getting stronger in chunks. 
 
I also preferred the hacking mini games in ME1 than in ME2. Sure it was the same mini game throughout the entire game. But it was fast. The connect the dots hack just seems like a waste of time and really tedious, and I hate the code hack. Even with my HDTV, the blue text and white text look identical when they are next to each other.

I'm perfectly fine either way, I found both perfectly fine. 
 
And as far as weapons go, I vastly prefer ME2's system, although I want more weapons for ME3.

I could go with either or for experience points.