this was exactly what we wanted for our stay. four people, two couples, were very comfortable here. things to note:
I think it would be difficult to cook in the kitchen. we didn't have a need to so it wasn't an issue, but if you're a tall person the slanted ceiling is a bit problematic near the microwave. as other reviews have said the lighting in the kitchen isn't practical for cooking.
the beds are comfortable, and the living area is very spacious. as others have noted the bedroom walls don't go up to the ceiling, so yes you'll hear everything.
to get into the building you have to go up some external stairs, and then to an elevator. you'll have to ascend more stairs after the elevator, so if someone has mobility issues (or even extremely heavy luggage or something) this might be an issue.
there is a bar/club in the building so you will for sure hear extremely loud music late into the night. but it's a city, so there will be noise no matter what.
the bathroom window doesn't have a curtain, so when one of the men went to use the facilities they looked out at another window across the way and saw someone cleaning the window. you can easily hang a towel up over it if it's bothersome, though.
overall this place was perfect for what we wanted: a comfortable and convenient flat to explore Montreal from. it's close to so much, and you can very easily walk to major attractions from it. for those who want to go out and explore and have easy access to everything, this is the spot!