need a good fx changer in toronto

It seems like this might be a decent time to change our USD to CAD. Well, it was some time ago actually, I've kinda missed the boat. But I'd like to be ready if I see another good rate.

Unfortunately I'm finding that diff FX changers give diff rates. Some can be quite significant. Can y'all recommend any place?

Btw would anyone have any thoughts on when it would be a good time to exchange the funds? I realize no one can completely predict the market. But we can make good guestimates.