Just so people know my bias I'm a former lunatic Marriott Platinum Elite member who has now settled gracefully into Gold Elite status (25 - 30 hotel nights @ Marriott properties per year seems to be the limit at which I don't start to regret/hate business travel ...)
This property has not received the facelift that a lot of US-based Residence Inn's have been getting over the last few years but it's also an established building rather than new construction so that has to be taken into consideration.
My room was fine, kitchenette & bathroom were some of the smallest I've ever seen in a Residence Inn but again that's a factor of the building layout. Room itself was very spacious and comfortable. The roof deck is a nice touch.
Staff were fine. Biggest facility complaint is the slow speed and tiny size of the three elevators. I can't imagine trying to get down from the 18th floor at the same time a bunch of people are trying to check-in or out. I intentionally left early in the mornings and walked up the stairs to the roof deck to minimize soul-sucking elevator wait times. More than a few elevator buttons had their call lights/illumination not working.
Wireless internet is free and (more importantly) speedy enough to get work done. One trend I noticed in 2010 is the horrific state of hotel-based internet service. Free or not-free just about every hotel I've stayed in this year has had almost unusably slow or intermittent internet service. In the US I can get around this with a Verizon 3G card or Mifi but I was mostly at the mercy of the hotel internet while in Canada.
Location is flat-out excellent, it's within walking distance of all sorts of touristy, shopping, dining and of course the McGill campus. Multiple subway entrances are a short walk away.