I have to say that even if i was excited about the movie from the trailer, when i saw the poor job that was done with the posters or the promotion i had doubts about the film. Surprisingly was much better, than both X-Men: Last Stand and and Wolverine films!
The story again was a little messed up (as far as i remember from the original stories) but as whole was better. I think it's bigger than the rest of X-Men movies and more serious. Still, they managed to make it light and really funny at moments (Wolverine guest stars!) with its strongest scenes in action. They had some references in to the previous movies or some of the X-Men future, so if you follow any of those you will grin or laugh a lot.
The acting was better as well. Even though there are only like 2-3 big names in. The only actor i didn't like was Jennifer Lawrence. Neither her acting or her as Mystique were convincing. Especially when you had the old Mystique to compare. Both James McAvoy and Michael Fassbender stoop up to their roles as Prof. X and Magneto, though.
Special effects were really great. It was difficult to get used to Frost's diamond self but she was okay. The music didn't match with the scenes at times, or at least that's what i felt. And there are many POVs in the film, which means you change places and atmosphere a lot. Something that took some time to get used to it.
Overall, was a great movie. Even though it was over 2 hours, i didn't get bored or wished to end. It kept me in from the first to the last scene and i can easily re-watch it, anytime. I believe the movie is also available in 3D, but for what i saw i don't believe it's worth it.