We stayed here October 2022 for a week with four adults and five children ages 9-13. It was perfect! With three bathrooms, and beds for everyone, the apartment was just what we needed. We could have fit our group into three or four hotel rooms for about the same price, but it was awesome to have a large living room/dining room to relax in after long days of exploring Paris. If you have a group like ours, this is the ideal place to stay!
The bakery right across the street was convenient and delicious. The Franprix grocery store was about 10 minutes away--we usually hit it after a day of adventure on our way home from the subway station. Multiple subway options are about 10 minutes away from the apartment. You can walk to Notre Dame in about 25 minutes (and it's mostly flat!). Other reviews have mentioned the street level noise--we heard some people late at night on the weekends but it wasn't enough to keep us awake.
The apartment is one floor up from ground level in a nice neighborhood. You'll unlock a door on the street with a keypad, then another door on the building with a keypad, then a physical key to the apartment. We felt very safe there and in the surrounding neighborhood. I would recommend getting a private shuttle from/to the airport rather than dragging your luggage from the airport to the apartment via public transportation. It's far less stressful, and you are much more likely to be pickpocketed if you are trying to get yourself and luggage onto a crowded subway car.
Once you're settled in the apartment, get the "Navigo Decouverte" transit pass. You have to buy it from an agent at the airport or in any of the major metro stations (not from a machine) and you'll need a passport-size photo, so get those made at home before your trip to save time and money. It's much cheaper and better than the pass they market to tourists. It's valid on everything in the city (buses/metros/trains).
The host, Alexandre, was great to work with. We were able to leave our luggage and use the restrooms when we arrived well before the check-in time. The cleaning crew got the place spotless prior to our arrival.
You won't regret staying here!