I often stay at the Sheraton when on biz travel to Toronto (a couple of times a year). For me, the product is far superior to comparable properties in North America at the same price points and definitely better than the other Marriott options in Toronto.
I have stayed at many of the super lux properties across Asia and there is no question that the quality of those offerings is superior - but what difference does that make? Until there is a BKK Luxury Collection option in Toronto, I am not sure why the comparison is relevant.