If you think Borderlands 2 is just more of the same you have no idea what kind of mechanics make a loot game good. The amount of reiteration, rebalance and polish to the systems was amazing, itemization alone was shot up an incredible degree, before even getting into the skill, effect and character design overhauls. Plus the fact that the actual shooting model is actually good now and top it all off with a much better paced and varied campaign, one with an actual end game and proper difficulty scaling, and it made for a much better experience.
I don't usually go after anyones tastes or bother to argue much, because I usually don't care, but in my mind you have to have some truly fucking weird priorities if you're veering towards BL1 over BL2. Honestly, BL1 was kind of a piece of shit, it worked as a good show of concept but was so bland, so empty, so poorly tuned with terrible classes and one sided item-work it just wasn't that fun to play until the DLC hit.
I slammed on BL2 all year, expecting it to be a bit of a mess like the original, and instead I put more time and came away happier with it than TL2 or D3, that's the mark of a damn good game.