There's a fair difference between 3D presentations in an IMAX cinema which are awesome, and an ordinary movie on the IMAX screen.
The first impressions of ordinary movies are of the sheer size of picture - which is why sitting in the centre of the hall is good, whereas with 3D, you are literally dodging out of the way of the things which seem to fly out the screen at you!
The sound is good too, but not really (in my view) much better than a well set up multiplex.
Whatever you think of Batman, try to see a 3D film there too sometime - that's a really great experience.