I was able to see this yesterday. Let me say that when I first heard of this movie, more than a year ago, I was suspicious of it. It sounded like a way to make the proposed Magneto movie more commercial, and with the release date assigned before the movie started production, I doubted it would get made in a timely fashion, or be very good.
I'm glad to say I was wrong. The movie is great, probably the best in the series (only X2 comes close) and one of the best of the genre. Setting it in the early 1960s was a great move - it gives the movie an identity, and sets it apart from every other comic book film, many of which have been popping up on movie screens with increasing regularity since the first X-Men movie in 2000.
My favorite parts of the movie are with Erik as a Nazi hunter. His visit to Argentina might be the best moment in the movie. Michael Fassbender was terrific, as was James McAvoy. I enjoyed the whole cast, really - although Kevin Bacon - who was good - is too recognizable as himself; it takes you out of the movie to see a familiar "movie star" face. I also enjoyed how the script played with X-Men history (though I might liked to have seen the original five members of the team as written by Lee & Kirby). Nice cameo work too. (Wink Wink.)
I've long thought that comic book movies should be period pieces. The creation of certain characters are of a particular era. To me, there is something about Spider-Man that says "Greenwich Village, circa 1966." Likewise, the X-Men and the Fantastic Four call for the Space Age. I also think these characters' stories should be finite, which is not to say they should all die at the end, but rather than see their adventures go on forever (as necessitated by the commercial realities of the comic book industry), there should come a time when they walk off into the sunset. I always thought the X-Men had a pretty good 20- or 25-year run. Taken as a whole, their story from 1963 through the Phoenix storyline (circa 1980) is great; they had a few good years after that, but by the 90s, the cast became so large and the universe so big and convoluted, it was impossible to keep up, IMO. (Of course, I also stopped reading it in the mid-to-late 80s, for the most part.) So many of these tales don't end well, it's nice to see a movie set at the beginning, where optimism and hope are more prevalent than gloom.
Let's see another one with this cast.