The Hilton is a nicer hotel vs the DoubleTree. Location of the Hilton is a little nicer though there's nothing wrong or unsafe with the DoubleTree. I personally prefer the restaurants in the DoubleTree vs the Hilton though.
We also have a Hilton Garden Inn on Peter Street in downtown Toronto. (I'm assuming a Garden Inn consumes less points.) If you want to be downtown, you may want to consider this as an option.
If it matters to you, the Hilton has more amenities such as a pool, larger conference facilities etc. Of the 3 properties we're talking about, in my mind Hilton > DoubleTree > Garden Inn with respect to what I would expect from a room and general service / services at the hotel.