I was only in Montreal overnight to catch a morning flight, but Christopher and Fatine's apartment was a great place to stay for that purpose. It's just a few minutes' walk from the airport bus stop and close to a load of restaurants (including a couple of good veggie choices). Christopher and Fatine were interesting and welcoming - exactly the kind of people you'd feel comfortable sharing a house with. There was a bit of street noise (it was a Friday night), but nothing I couldn't sleep through.