The last 3D movie I saw was Avatar and I didn't like it. The way the 3D forced you to focus on what it was "3D-ing" didn't sit well with my eyes/brain. So I wasn't going to see Gravity in 3D...I just wanted to see the IMAX version. Well, poor planning lead my girlfriend (who had the same experience in Avatar) and I to the only IMAX around not realizing that on some days they show Gravity in 3D and others they don't. Yesterday they did.
The skinny for me is: You should see it in 3D. It's a movie built for it. Since most of the shots use space as a background - i.e., darkness - there's nothing for you to focus on except what the 3D is focusing on. And some of the shots are incredible: the ISS exploding and the Northern Lights, in particular. The only scene I can recall that messed with my head some was the teardrop that floated away from Bullock's face. Anyways...I guess my point is that if you had a negative experience with 3D in the past, now is the time to give it another shot. It was a much different experience for me...and WELL worth it.