We had a lovely stay at Sarah's flat. The neighborhood is absolutely charming, and pretty walkable to everything we wanted to do and see (put on about 10 miles/day) but in the lovely fall weather and cute streets of the neighborhood and city we didn't mind walking at all!
Sarah was so friendly and quick to reply to all of our messages - offering suggestions on best places to thrift shop, and tips on finding a free parking spot for the weekend. Definitely appreciated!
The flat itself was very clean and pretty big - had everything my fiance and I needed; with a very comfortable bed I may add! The only small bump in our stay is that I believe Sarah and Aristide have a small child/children who we heard running around every morning at 7:30/8AM. We love kids, and have a few nieces and nephews ourselves, so we totally understand that they have a LOT of energy in the morning - but a heads up for people who like sleeping in late - this wasn't a huge issue for us as we are fairly early risers, but just worth noting.
Overall - great first time to Montreal! Would love to come back someday!