Excellent apartment in a wonderful neighborhood, near enough to the center to be convenient but far enough out that you feel as if you are getting a look at the "real" Paris rather than just the touristy parts. Cyril is a wonderful host and responded promptly to all concerns.
The only negatives are the lack of air conditioning (normal in Europe and normally not a problem, but we were there during unseasonably hot weather for a couple of the days of our week-long stay) and the six flights of stairs you have to climb. They're a good workout for a reasonably fit person and didn't seem too onerous once I got used to them, but some other members of my family found them quite difficult and prospective guests should be aware of this and make sure that a 6th-floor apartment suits their needs. Neither of these things are in any way Cyril's fault--he was clear about the six floors in the AirBnB description and did everything he could to help us deal with the heat problem.