We went with a large group (9), and all enjoyed it, but some more than others. Natalie Portman is "perfect" in the role, and deserves Oscar attention. The movie is very thought-provoking, and I spent the next day reviewing it in my mind. It definitely is not a feel good movie, but I'd like to see it again now that I know the ending. It's difficult to discern what's reality, but that's part of the thrill. Don't go if you're already depressed, because it might put you over the edge! I felt it was definitely worth seeing, if only for the exceptional acting and dancing by the actors.
I'm afraid that I'll be spoiled for "regular" (non IMAX 3D) movies! It was like actually being in the movie with all the action, gorgeous colors, animals,etc. It took movies to a new level, and we all thoroughly enjoyed it!