is a "small" imax worth it over normal 2d? my local cinema in the arse end of nowhere opened their so-called "imax" screen tonight and i found out it's 90m². compare that to BFI london... 

The BFI London IMAX is the largest cinema screen in Britain. It measures 26m by 20m with a total screen size of 540m². However if showing a film with an aspect ratio of 2.39:1, only 283m² of the screen will be in use, or 365m² for a 1.85:1 film. The auditorium seats 485