When I first bought the game (which I think was a few months), I either played solo or splitscreen. I didn't really like the idea of playing with randoms, but at one point I tried it anyway. Kinda ruined it for me, and I had a ton of quests that I knew nothing about. I returned the game within a week.
Picked up a $20 PSN card at Gamestop, and man...is there nothing worth $20 on there. A friend and I share an account, so I bought it on that one and we started playing the next. Played every mission with him from beginning to end and it was a great experience, one I don't think you could get by playing with random people.
The only problems I have with the game itself, is the terrible scaling. The balance is damn near perfect at the beginning of the second playthrough, enemies aren't too strong but they aren't too weak. By the time you get to Mine Key mission, enemies are pretty much walking tanks. It's funny however, that ALL OF THE BOSSES SUCK. We beat Sledge literally under 2 minutes. Hell, I wasn't even shooting him...
It gets worse as they game goes on, and I fear they haven't fixed the scaling in Borderlands 2.
If you guys have any level 40-50 characters, I'd love to play with ya. Just got to the Dahl Headlands
PSN: TheJx4