Saw it on IMAX in Louisville, although I was disappointed that the "IMAX" screen there is simply a large letterbox format, not the more square (and super huge) IMAX format. It was still better, but almost like watching a 2.35:1 movie on a 16:9 widescreen TV. There was very narrow letterboxing, only to fully fill the screen during the IMAX scenes.
It was an IMAX at a movie theater.