My mom, two daughters, and I stayed in this charming apartment for 7 nights. The adults claimed the bedrooms while my daughters actually enjoyed sleeping in the family room on the futons.
When we left the apartment their was laundry detergent and dryer sheets in the cabinets as well as soap and body wash in the shower. That information may help you when packing.
The kitchen had enough supplies for me to make a nice dinner most evenings (microwave, full oven, stop top, small fridge, and toaster). There is also one AC unit above the kitchen table for hot stuffy days.
We drove and had no problems with parking at the apartment. The street in front of the apartment was almost always vacant. If not, or if it was the one hour a week you couldn't park there, you could park across the street or on the side street.
The grocery store was literally a 5 minute walk from the apartment and had anything and everything you could need during your stay in Montreal.
If you are planning on doing most of your site seeing downtown then it will take you awhile to commute back and forth. Luckily that wasn't the reason for our trip but we did drive down there a few times for the major attractions.
I would definitely recommend this charming apartment over a hotel.