There are two kinds of studios in Calgary - yoga studios that offer hot yoga and hot studios that offer yoga. Yes, I've said this before (and will say it again). Passage is, generally speaking, the former.
Recently, Passage has been through a transition both in its space, undergoing a recent renovation to its hot room, as well as in its teaching staff. While some instructors are seasoned pros (I love Gord), there are a lot of new faces. Overall, a good studio, and if you want a ridiculously tough/awesome power flow class, you need to attend on Sundays at 11am.
Valuable sidebar: I'm not sure there are any studios with more competitive student rates. Just saying.