The unit was very clean, and was wonderfully-located. There is a metro station very near by, which makes it very easy to get to and from the airport (take the 747 bus to Lionel-Groulx, then hop on the metro to Sherbrooke). It was also easy walking distance to many fun parks, shops, restaurants, and bars.
Vladimir and Valentina provide a big breakfast each morning, which is a nice touch. They are also very easy to get ahold of, because they own a shop on the ground floor of the building. They are in the shop from 10:00-23:00.
Located on a cute pedestrian mall, the unit can have a bit of street noise at night, but that's the price you pay for being in the middle of things. Consider earplugs if you're a light sleeper.
The perfect spot and highly recommended for 1-2 people. 3 could probably get by ok, though the bathroom might be a bit crowded. I probably would not recommend for more than 3 people unless you're used to being in close quarters.