If your partial to SPG properties the Sheraton is going to be closest to the action. If you want the closest decent hotel it will be the Courtyard. (Stay away from the Days Inn DT) I would also recommend Priceline for Toronto vs. using points or paying outright if you are open to the hotel location. There are some pretty good deals to be had. (We got the Sheraton one time for $62 a night and the Renaissance which is not optimally located another time for $63....but that was when the economy was still good and the Courtyard could go for $169 a night.) According to the Better Bidding site rooms are currently going for $52-55 at some 4 star hotels. Check out the following link if you are not familiar with the site:

http://biddingfortravel.yuku.com/for...to-Ottawa.html

It has some pretty interesting details on it but some don't like it because of the person running it. I've found it helpful with the 3-4 Priceline stays I have booked.