I, for one, enjoyed it. I went in looking for a popcorn flick and that's what I got. It was fun. Had I been a hardcore X-men fan, perhaps my views would be different, but other than a smattering of ideas about who had what powers, I have no idea what the backtory is supposed to be.

So, to me, the effects were cool, the mutants were cool, and I enjoyed the story. So there.