I have visited countless movie theatres in Toronto for years, but I have to say, hands down, this location is by far the best. With a fully equipped IMAX and UltraAVX theatres, you can bet there's a movie for anyone. There are giant escalators and stairs, which you can take your pick during a movie premiere ;)
I usually pre-order tickets in bulk for about $7 each with corporate discount, so I only have to add $6 to watch movies in IMAX.
What I miss the most is the IMAX laser show. When I enquired, this location is apparently one of the last to abandon it.
IMHO, the only movies worth watching are in IMAX. It's not worth paying money to see a movie with sub-par quality. The upgrade is definitely worth it if you have money to spare.