I didn't see it at an IMAX theater but I was surprisingly impressed by the 3-D effects. A few months ago I was at a computer show for vendors and watched a 3-D demonstration using electronic glasses that blinked polarized lenses as shutters. Whatever method was used in Avatar used glasses but not electronic ones. The effect however was as good as I recall seeing at that computer show and the screen was WAY BIGGER.
The movie was like a combination of Vietnam, Dances with Wolves, Aliens and Fern Gully.

http://en.wikipedia.org/wiki/Ferngully
Heavy on the Fern Gully.
http://www.thedailytube.com/vi...-presents-fern-gully
http://www.youtube.com/watch?v...eature=youtube_gdata
It totally blows away Star Trek which had nothing to say and beats it for effects. I am going to go again soon which I haven't done for any movie since The Matrix. That was 10 years 9 1/2 months ago.
http://www.cinemablend.com/new...ee-Avatar-16208.html
psik