Great location and is mostly quiet except for the thumping club that started up at 10 pm on Friday and Saturday nights, along with a few drunken patrons heading home in the wee hours of the morning. Sonder provided pre-packaged earplugs for the occasion, but it wasn't really that bad.
The room was big enough, clean, and comfortable, with essential accouterments provided if you want a kitchen. I recommend staying here as it is located in a great area of Old Montreal with short walks to plenty of good restaurants and bars.