for a person thats lived in all three cities (Montreal, Vancouver, and Toronto), i can clearly say that the worst of all three for techno is Vancouver. Actually, Vancouver is just terrible for nightlife in GENERAL.

Toronto used to be very big in terms of techno during the days of Kenny Glasgow and Mario J, but even now i think no one really plays out in Toronto on a regular basis except for Greg Gow. Recently there was a very big party at the Guvernment with Richie Hawtin and Carl Cox. That will be the only time when you see big names coming through the city; when it is a overpriced massive, packed with ten thousand people. Overall, techno in toronto is relatively quiet on the whole, but promoters will successfully cash in on parties by bringing in superstar DJ's to large venued events.

Montreal has been lagging alot lately, but still has a healthier scene than Toronto or Vancouver in terms of techno (not sure about other kinds of music though).
The hype and consistency of techno in Montreal has waned through the recent years, but in general Montreal can arguably still be considered the techno capital of Canada. I think the only people who are still even doing anything these days are Misstress Barbara, Preach and Yaz/Miko and Mateo Murphy. Im not sure if many of these names even play in Montreal on a regular basis anymore, but im sure their contributions to the scene can be widely felt.

Anyone who wants to get booked in Canada and wants to play techno should try to get a gig in Montreal as it seems the French are a bit more open to techno....I havent been back to Aria/Stereo/Sona or any of the old clubs that people used to go to for techno, but im sure there are still many techno enthusiasts and appreciators in Montreal despite the recent downturn in the scene.

Hope my comments helped.

peace!