Thanks for the replies. I had searched of couse, but many of the threadds were quite old- many from before the W opened in Montreal.
As this is a one night stay just for a quick look around the city, then the Versailles might be best value. I am a SPG Gold, so the queen room should be ok, hopefully not too small!
Looking at booking the three nights for the price of two promo at Westin Times Square, though holding off in case there are any good offers from any of the W hotels!