I just saw X2 again. It's worse the second time than the first. My major argument is still that it just isn't a very good movie: pacing is slow, characters are 2D, climax is drawn-out and unfulfilling. Once they get past the new special effects (which all seem to be in the first 45 minutes), there's not much left. And the ending? I finally saw it with some non-fanboys and they were completely lost and frustrated by the ending -- not to mention much of the rest of the action. (Jean can destroy missles but not lift the jet from inside? Sure, there may be a comic explination, Foster, but they left it off-screen.) X2 is just disappointing.
The one bit of good news from the second viewing: Franklin Richards.