I liked the movie, but found the continuity issues significant to the point of distraction. And while I smiled at the Wolverine cameo, it also made me cringe, because it never happened and slapped the first X-Man movie in the face continuity wise. Also, I thought in the first X-Man movie it was stated that Cerebro was built by Professor X and Magneto, but this movie indicates that Hank McCoy built it - and apparently McCoy is such a super-genius that he built everything...even their modified SR-71 Blackbird. Oh well.
I did like the Magneto back-story, and appreciated the time they took telling it. By far the most complex and interesting character in the film. I also didnt mind Shaw either, and thought Kevin Bacon did a pretty good job as the bad guy here.
Liked the movie, but would have liked it more had it been consistent with the other movies and messed with the canon less.