So, I've seen the movie 5 times now, including once in D-Box and once in IMAX.
D-Box is a neat gimmick and I missed not having the motion/rumble in my subsequent screenings, but after watching it in IMAX, I'm convinced that for 3D films, IMAX or I guess even LieMAX is the way to go if ONLY because of the increased brightness of the projector bulb.
Standard theaters probably get away with fucking around with cheaper bulbs, so the first three times I watched the film, it was unnaturally "dim", but when I watched it in IMAX, I was seeing things I just didn't notice the first time around because of how bright everything was (by comparison).
I *almost* want to watch the film in 2D, but I suppose I'll just wait for the BD.
That said, after 5 times, it still holds up. The opening long take is still amazing to behold. And man, the last time I watched a movie this many times in a theater was Saving Private Ryan... here's hoping I don't feel bad about being a Gravity fanboy 10 years from now. lol