Borderlands 2 is a visual treat and the "shoot and loot" concept makes the game highly addictive. At times, the utterly hectic action can be fantastic fun and, without reservation, it's a game you should buy.
But there are problems! There isn't a difficulty setting and people find the game too easy or too hard. The entire game is carefully balanced, and that balance is easily upset, leading to unrewarding play. Also, despite being coop, it's almost impossible to play with friends, because the levelling system makes a huge difference even if you are only a few levels different to each other.
And don't make the mistake I did and buy the Season Pass. The DLC just isn’t up to the mark. The maps are well designed, but the campaigns and loot are really boring.