Pros: The apartment is centrally located in downtown Montreal, but the street itself is quiet. It's near many restaurants, and a short walk from Place des Arts and from the metro station. The hosts are friendly. The price is affordable.
Cons: While the street is quiet, there is not much soundproofing inside the unit, so you have to hope that the other guests and the neighbours will be quiet. (The hosts do have a quiet policy, but there's only so much they can control.) My mattress felt worn down in the middle, and I would not want to sleep on it if I had back problems, or for several nights in a row. My room was clean but some of the common areas could maybe use a little more attention.
Overall I was satisfied with the experience.