Could be a nice stay in Paris, location convenient to public transport, while not really very close to the attractions.
The duplex flat is on the 1st and 2nd floor, good size of space, with attached toilet and bathroom in the court yard. Photos are accurate, the staircases to be careful.
Environment is safe and quiet however the noise could be from upstairs as usual in a Paris old apartment.
Only problem could be the check-in. The location to pick up the keys could be an issue if you have luggage. Late check-in better to double confirm for time.