The classes in BL1 were a lot more distinctive. For example, the soldier was the only class in BL1 that is able to heal teammates, to my knowledge. But in BL2, I know that at least the commando and the siren are able to heal teammates. Some people complained that the original story was almost non-existent, but if you read the mission blurbs, you could enjoy it. There's a vid on youtube of all the unused voicework left in the game, it was all scrapped when they decided to make the game more comical rather than apocalyptic drama.