Our group of 7 were very comfortable in this 3BR apartment (not listing says 4BR but there are only 3 BR plus a pull out couch in the living room). The location is ideal, right in the heart of Old Montreal.
The place was very clean and the bedrooms well-appointed, comfy beds and plenty of pillows. If you plan to cook, there are plenty of pans, dishes, utensils, but no staples like salt/pepper, oil, etc.
The communication with the host was hassle-free, and they even include parking for one car a few blocks away.