Overall a very good place to stay in Montreal. It's not particularly close to the "downtown core", but getting there is easy enough via public transit. It's about a 10 minute walk to the blue line and a 15 minute walk to the green line, both of which will get you all over the city pretty quickly. Mount Royal and the various attractions surrounding it are all very close - the mountain itself, Saint Joseph's Oratory, UofM, and a bunch of restaurants along Côte-des-Neiges. You're never really too far away from everything the city has to offer.
As for the apartment itself - I didn't really have any issues. Everything was clean and tidy upon arrival and exactly as described. The apartment door has an electronic lock and the main building door is unlocked using a keyfob provided by the host. The only real concerns with the building was the elevator and the laundry. The elevator is the definition of the term "death trap". It's old, very slow, jerky and generally not enjoyable at all. I'm sure it's not dangerous, but it sure goes out of its way to make every second spent inside of it feel like it may be your last. And as for the laundry - it's coin operated and found on the main floor of the building. There's a change machine nearby that ate our $5 bill, but our host was more than happy to sort that out for us so no harm, no foul.
All in all, there are no "real" complaints about the place and a bunch of compliments for both the host and the location, so I can highly recommend both Kim and her apartment for anyone looking for accommodations in a less-busy part of the city that still makes it very easy to get around and explore.