He's actually one of my favorite characters. I don't know why everyone hates him, he's cocky but that's just the funny part of his character. He has also had some nice moments in the series, especially in the search for sasuke arc. Part 2 he has done nothing but neither have the rest of the K11. People think that hes bad because Kishi uses him for comic relief but he's obviously better than he was in part 1. He hasn't had a serious fight in part 2 so he hasn't had a chance to show off any improvements.
And if Choji can turn from one of the worst ninjas of all time to a Super powered butterfly man in 1 sec than anything is possible.