I personally went with RBC (though mine is in Quebec, and I think it's slightly different from Ontario).
Scotia and RBC are pretty close- seems like iit's the representative you talk to and the bank you may have had the most exposure to that are the deciding factor. So, for me, I've already been with RBC for a long while and have done well, plus the rep I have been dealing with from RBC (ioan jurjan) has been great, plus the perks of the LOC I was able to have set up. All this made RBC the clear choice for me personally. But again, it depends on the rep you speak with, and your own experience.