Just got my copy this morning.
So far it definitely improved on everything but there's one thing that bugs me. The enemies spawn too fast in areas that you've just cleaned.
It happened 3 times (level 9) already. I killed every last enemy and everything is quiet. I move around a bit and look for loot. Then after a minute of checking if that new found weapon is better than my current or not I turn around and suddenly the enemies come out of their huts again even though I never left the area.
Never happened in the first Borderlands to me. Extremely cheap when you're suddenly surrounded by fiends that you just killed.

I agree!  Dunno why they didn't do the respawn when you leave an area and go back to it.  With all the loot, the stats, we indeed have to stay put and look into our backpack.

I think it takes like 30 minutes for them to respawn so I dont really see the problem I prefer the way it is

They shouldn't respawn at all unless you leave the area. What kind of sense does that even make ? Where do these new warriors come from ? The toilet ?
Then I'm pretty sure that this is a bug. As I said it happened to me 3 times so far, but there were many more opportunities where I spent much more time in a certain area and nothing happened (thankfully).

I think the only thing that I'm a touch disappointed in is that there doesn't SEEM to be any weapon proficiencies. You can use the badass ranks to improve your stats, and I know the skill trees allow you to chose what weapons you get better at (my commando has an 'improve damage and mag size with assault rifles" perk), but you don't seem to get experience with your weapon by using that weapon type. Is it in the challenges list and I didn't see it or something?

Playing Co Op with my brother. am at level 15 right now, just....well, no spoilers.

There are challenges where you need to kill 200 foes with assault rifles etc. in case this was your question.
Completing them obviously won't make you better at assault rifles, but instead give you a new badass rank like every other challenge.

well that's just lame!  I liked those proficiencies!  gave you incentive to master something and personify your character.

It's fine. I felt proficiencies were overpowered, well, they would be in BL2 at least.

Bought the game day one. Was completely sold ever since I played the first game at my cousin's house a few months back. They definitely improved and tightened up some of the faults in the first game. And man, all I can say is, this game is damn near perfection. Best multiplayer RPG hands down, I think it even dethrones Secret of Mana in that department. Been playing it all night long the past few nights with my cousin and my friend, and I have to say my lvl 20 siren is kicking some ass.

Was never interested in the series but with Borderlands1 given to me free from PS+, the gamer within couldn't simply ignore the chance to see what the fuss was all about. Started it over the weekend, mainly Saturday and i'm currently a lvl 19 berserker (didn't touch it today). Something about the game that makes it hard to put down (playing solo). Not nearly as engaging and fun to explore as Skyrim but it grips me in a similar fashion.

I'll if the experience continues to hold up, I'll be being the second one when i'm done with the first, a few other games, and consider another game to play.