I've been using newyork and chicago voip.ms servers for the last 3-4 years b/c I've always had issues with Toronto. It's not even in Toronto, it's at some cheapo DC in Hamilton called Carat Networks. -- Fiber Optics are the future of high-speed internet access. Stop by the BBR »Fiber Optic Forum.
Well, I'm tempted to try the Montreal servers. I used the Seattle server last week for a few days and it was crap - call quality suffered.
I use the Seattle service in a number of cities including Toronto and I haven't had any significant issues with it. As long as the latency from your location to the server isn't ridiculous it shouldn't be an issue.