I saw this movie twice in one week. First time in 3-D and 2nd time in IMAX 3-D. I did not notice a difference except the IMAX glasses were more uncomfortable. Perhaps if it was a true 7 story IMAX screen I'd feel differently, but ironically the IMAX screen I saw it on was smaller than the 3-D screen. My husband and I saw it the first time, not taking the kids because of the PG-13 rating (ages 7,9,11). It was an exceptional movie, and we went back with our kids to see it again. I wanted them to experience it in the theatre. It is well worth seeing on a large screen, and in 3-D. It is definitely one of the best movies I've ever seen. James Cameron did an excellent job creating a world that is believable, and beautiful.