I spent a few weeks in Toronto for work each year:
1) Canadian beer is terrible. It's a well known fact that Weihenstephaner is the best. Luckily, most decent Canadian bars will carry this (just like decent American bars).
2) Tim Horton's is basically garbage but they're proud of it for some reason. At least Americans aren't proud of McDonald's.
3) The politeness is overrated. It's just like Midwestern politeness. It's partially fake and the moment you make some minor mistake/transgression you're in their shitlist for a long time.
4) I did like the weather though. More southern and a good deal warmer than home.