Just got out of the theater a couple minutes ago. I can't believe how much I liked the 3D conversion. As someone that usually despises 3D, I didn't get a headache or find it obnoxious in the slightest. They really used it intelligently.
As for the movie, It's still my long time favorite, and seeing it in Imax was worth every penny. Was holding my breath without realizing it during the first scene with the Tyrannosaur, and everything looked so crisp. The sound was almost the best part. The Tyrannosaur roar was deafening.