I understand some of the gripes. It certainly is not the film that Singer would have done. No, it does not mirror the comics storyline or character development, although there are certainly enough nods to those that any enthusiast's zeal should be sated. But still, purists gripe.
Is it the final episode? I've heard complaints about this. The vacuous Halle Berry has stated in interviews that if fan support was strong enough she has no doubt there would be a fourth installment. For those who doubt that it could be done, that there were too many changes in the storyline, think on it.
There were deaths, yes. (I don't feel this is a spoiler... I think it's expected.) Characters were altered during the story, and some came out very differently than they went in. BUT! Nearly all of these details can find a near match in the comics. Every named mutant that died, indeed nearly every named mutant in the film, has died at one point or another... and they "got better" through whatever plot device was convenient at the time.
I went in to the theater, and immediately suspended my disbelief. Ghost Rider? SWEET. A large part of me, possibly my immortal soul, cheered that I was seeing Nick Cage in that trailer instead of the Superman one. Honestly, Johnny Blaze had me more pumped up than the Man of Steel, but Kevin Spacey makes an excellent Luthor. It certainly looks to be an interesting film.
And those previews certainly got me pumped up for the main attraction. Thankfully, I didn't see enough previews and spoilers described as reviews that the entire plot was laid out for me... I was able to detach from my current worries and take on the attitudes of the oppressed mutants and heroes of the film.
Good times.
Quit whining.