Toronto and Kitchener-Waterloo are both healthy, vibrant startup hubs, but are distinct regions IMO. They are 120km apart and it takes ~90min to drive from Communitech to MARS https://goo.gl/maps/vRJqc7JsNcp.

Both positively influence each other, compete for resources. Waterloo has some more affordable suburban housing, and less vibrant city/'downtown'. Toronto is more expensive, is bigger and better in many respects.

Vancouver and Montreal are also decent startup ecosystems. I've been writing a researching Canadian cities/startup ecosystems for a book. Lots of stats and resources here if you're really into this topic: https://github.com/DeBraid/ham-innov-essay