I'm so disappointed... one of the guys I went with this weekend said I picked the "wrong" Imax- that there was a much bigger one on the south side of Denver. So, I realised that I got a smaller screen, but I didn't realise that my screen was that much smaller. Damn psuedo-Imax.
I'm surprised this IMAX issue is new for people. The IMAX process requires expensive cameras and film. Very few Hollywood films are shot in IMAX. Sometimes, as with the Dark Knight, some scenes will be shot in IMAX, but even this is rare. The IMAX projection equipment is gigantic and will not fit in a typical multiplex. If you are going to a multiplex, it is almost certainly a high-res digital presentation and not the 15/70 IMAX you might find in a museum.
The reason to go to the IMAX digital presentation is not the picture, but the sound. Most of the IMAX Digital theaters have been outfitted with the same sound system as traditional IMAX and are using it in a much smaller space.
The Regal 9 at Colorado Center is also IMAX Digital, but the screen is bigger than the Orchard. The only true IMAX in Denver is at the museum and doesn't have ST.