I'm a Starwood member and because of that feel obligated to stay at SPG hotels when I can to get points and build status. In the past, I've also stayed at Starwood properties (now a part of Marriot) because they are great. I fly a bit to Toronto and find the Sheraton to be convenient and a Starwood property so I stay there - but I don't enjoy it. There are pros and cons but overall all its the utility that brings me here and that doesn't inspire.
Pros: Great gym, nice continental breakfast with views if you are a platinum member, very good LG televisions with a great movie selection. The rooms also have outlets on the bedside table - iThe staff is friendly but at times robotic but they seem to mean well. The hotel is huge and for that reason a frequent choice for conferences - so it's often packed and the price per night is reasonable.
Cons: The hotel is ugly but a durable concrete that will probably withstand an air attack. The rooms are uninspiring even with the 10s of millions of renovations. The bath products (Shine) are terrible. The food options are average. On a recent stay I had the pleasure of electricity going out twice in the bathroom because of a tripped circuit breaker. The wireless is infuriating and spotty and overall terrible in rooms - I was told to go outside in the hallway and hold my phone up to the wireless routers to log on - but you are periodically kicked off. Even if it worked why is that the solution?
If you need a hotel that's downtown and won't break the bank and your loyal to Starwood and has a great gym - go for it. Otherwise don't...