The good: great location, stylish apartment.
The okay: the other reviews are correct, the walk up the stairs to the apartment is not easy. typical for Paris, but be prepared. and as others have also said, they advertise AC, but that is not true.
The bad: the check-in process was not good. we communicated when we arrived in Paris, and that we would like to check in. we arrived at 2pm (the earliest possible check in), messaged the host again - with no response. called, messaged, etc. 20 minutes or so later we're told someone will meet us to open the door. ultimately we waited outside, after a red-eye, with our bags for 45 minutes. zero apology from the host. we've stayed at similar airbnbs who made a deal with a local shop to hold the key. there are a few shops on their street, not sure why they haven't done it that way.
Also bad: the host scheduled a plumber for the middle of the day while we were at the apartment. the sink in the bathroom wasn't draining well, a previous guest complained, and they scheduled a repair. Along the theme of bad communication, they simply told us when the person was coming, and did not ask if it would interfere with our day or our sleep. the plumber also arrived earlier than they communicated. I suppose the theme here is: poor communication. hopefully they improve that for your visit.