Two separate comments, one for the place and the other for the host:
The Apartment was stunning, all of the pictures show the space exactly as is but somehow still manage to make the place look smaller than it is in person. There was plenty of accommodation for people to sleep, the two beds in the bedroom were very comfortable, all of the futons fold down into comfortable sleeping locations, the two pull-out beds were as expected, additional air-mattresses made for easily-removable additional sleeping arrangement, and there were plenty sheets and pillows for all of the above. The kitchen was well stocked (although we did not get much chance to use it) and the other living amenities supplied entertainment for all (a lot of poker was played). The location was fantastic. Some great little shops & restaurants on the street you are on, the Metro is a block away to get you anywhere downtown, and there is decent parking nearby.
The communication from the host was, however, a little poor. They are a part of a larger realty company that deal with many locations and seem to miss some of the details in communication that a single person may not. The day that I was supposed to arrive, they found a detail error in my reservation and ended up charging a lot more than was additionally confirmed. Partly an error on my part, but they were not very willing to work on the phone and left extremely little time to have any problems sorted out. This forced me to accept any changes they claimed were necessary and pay the high additional cost, even though the entirety of it was not needed. I am not sure if the little time to correct was intentional or not, but this was definitely a let down on the day of. This trip had been planned for a long time and there was plenty of opportunity for this discrepancy to be worked out before the day of arrival.
Overall, I would highly recommend this place if you are on your way to Montreal with a large group.