1) Leech does not look anything like the boy in the movie, not even a resemblance!
2) Beast is “thin” compared to the comics.
3) Juggernaut’s power comes from magic as such he is not affected by Leech powers.
4) Jean Grey being a Phoenix does not come from what the movie suggested.
5) Scott Summers is still alive in the comics
6) Professor X only died in the Age of Apocalypse series and not by the hand of Jean Grey.
7) Rouge is so lame in the movie, with the other members already having advanced powers they chose to put Rouge on the sideline cause it would be like putting a superman in the movie, super strength, invulnerability, flight etc. then she would have all the attention.

A lot of inconsistensies, so just like what I said if you’re a purist comic book fan then the movie is not for you. If you are in to special effects, then the movie is pretty good. So just sit back and relax, its a movie its not comics, it will never be as good as the comics.