I just saw the movie and I'm still gathering my thoughts. My initial thoughts are that the movie has an excellent concept and some very creative and thought provoking ideas, but the execution isn't quite on par. If I where to grade the movie right now, I would give it a B+.
edited to add: I am glad to see that Tom Hardy is making a comeback. While watching Star Trek: Nemesis I got the impression that he was a good actor who simply wasn't given a good script to work with. I liked his character in Inception.