Most importantly, the apartment is in the exact location you want to stay in Montreal - the Plateau with excellent shops, restaurants, and great street life. There are several excellent grocery stores within a few blocks and, if you're a cyclist, you'll be in heaven in Montreal. The apartment also was huge, with plenty of space for our family of 5. Finally, it was both stylishly and thoughtfully appointed. It's an older home, but feels mostly fresh and updated. We could have lived here indefinitely, which isn't something I can stay for most travel accommodations. Both check in and check out times were strict, but that's a testament to the home's popularity. Annie was also incredibly responsive.
One pointer if you arrive on a weekend: overnight non-resident parking in the area is very scarce, so if there's no attendant at the recommended lot a block away, park there anyway, leave a note on your dashboard, and settle up with the attendant by Monday morning.