The movie was OK - just OK. The review mentioning Fern Gully was right on - I kept flashing to it during the movie. The 3D was marginal - I was more impressed with the 3D at the Back to the Future ride at Disneyland 10-15 years ago. The graphics were well done for sure, but for $300MM they'd better be.
My big complaint was the IMAX theatre. I don't know how it works in Kansas, but where I come from (MN) an IMAX theatre (Science Museum of MN) the screen starts at the floor up front and goes all the way to the junction of the ceiling and the rear wall. The screen here (in Olathe) was just a rectangle. Not only was the picture compressed at the middle, but I wasn't impressed. Give me my 15 bucks back.