It was disappointing to watch an action movie on a newly constructed "IMAX" screen last Christmas. Why? Not because the movie wasn't entertaining. It's because the screen wasn't even close to the usual IMAX size. Click the image below to get a better view.
I'm not sure of the exact size of that screen but it certainly did not feel like IMAX. Apparently, this has been going on for many years. Cinemas are putting in "IMAX" screens within approximately the same space as regular screens and then charging $5 or more for the, er, experience.
Found a guide for Canadian IMAX theatres.