Overall, this is a decent place to stay in Montreal. There are pros and cons, like any Airbnb. So I will list those below. Given the number of options in Montreal, if I were to return, I would choose somewhere else.
Pros: The space is very clean and the two bathrooms are a really good size. There is plenty of space for a family of 4 (or maybe even 5) to easily spend the weekend. The TV has Netflix so, if you want to hang out inside and rest your feet, you can easily turn on something familiar. There is an IGA (grocery store) within walking distance as well as a convenience store so, anything you need is very close. As far as location, this apartment is on the outskirts of Old Montreal. It is on the "old Wall Street" of Montreal and among some beautiful buildings. It is absolutely within walking distance of the Old Port and everything on Rue St-Paul. Very close to Cafe Tommy for breakfast or Crew Cafe for coffee. That said, I would have preferred to be closer to the Old Port. Even a few blocks would make quick trips to restaurants just a little bit easier, especially when you are walking 20,000+ steps a day.
Cons: The beds are uncomfortable and are not queen-size beds - they are doubles. It is difficult for a family of 4 to get any sleep in this space. We did not. The couch is very comfortable, and someone would be able to sleep on it, but there are no extra blankets anywhere in the apartment. Not even an extra sheet. The air conditioning did not seem to work, so it was very hot in the space the whole time we were there. The second bedroom has almost no privacy, as it is open to the rest of the space. Anyone sleeping in that room can't go to sleep if the rest of the people in the apartment are awake. In the main bedroom, there is no outlet on the far side of the bed. The check-in process was frustrating. I asked several times for early check-in with disjointed responses. Because you are dealing with a large company instead of a single host, you get a different support person each time. I then received a call that I would have early check-in, and then minutes later got a text that there was a "broken curtain rod" so I could not. Overall the communication was confusing.