Mystique changing bothered me too and her CGI body was distracting. I also didn't like how flighty Magneto was.(SPOILER) He had just professed how much he missed Mystique and then moments later tried to kill her. Seriously, what in the hell? Everything else was awesome though. No issues here. Xmen 2 might still be the best, I'll have to watch it again, but it was definitely better than First Class which I thought was a bit of a well-acted borefest.