We've been there for two days to visit Toronto.
If you want to be close to the most important attractions, that should be your choice.
We've been located in Sullivan Street since they have more than one house for guests.
This particular house is very nice, with a full equiped kitchen, a lovely living room and wonderful rooms with free wifi everywhere (the house is shared although we were lucky there was nobody else).
The people who manage these apartments are lovely, Roger recommended us the most important places to visit in Toronto and gave us some good recommendations for eating.
So, this has been a wondeful experience in Toronto and I only can recommend you that place to stay in.