Sunnybrook is probably one of the better hospitals in all of Canada.
For the most part, it is very clean and well maintained in comparison to other hospital in the GTA, and the greater majority of the staff are polite and helpful (unfortunately a rarity in other Canadian hospitals from my personal experience).
This is a great hospital to be referred to for a specialist/or therapy. One particular issue is that a lot of people seem to recognize this and wait times for most doctors are not exactly short (as far as 60days. Thank you Health Canada).
Other issues with the hospital include its horizontal layout (it could take you a good 15 minutes to get from one side to the other), and the lack of food choices (stay away from the main cafeteria!)
If you do live in the area where you would have Sunnybrook doctors as your family doctor, just keep in mind that you will be examined by residents who are supervised by more senior doctors and this could mean a minimal 'lasting' relationship with a doctor as the residents will change every year or so.
Overall a preferred hospital when it comes to surgery, ER, or visiting a specialist, but beware of the wait times!