We stayed at the apartment for a few days and were very happy with the location, as well as the size of the apartment.
We had some issues with the check-in, a key was missing and we couldn't open the door. It was unfortunate for us, but these things definitely do happen and after we finally were able to reach the host, he did try to fix the situation as quickly as possible.
While the apartment in itself was ok, it didn't seem to be ready for guests to be quite honest. There was a rack with towels in the living room (we weren't sure if they were clean, since they weren't hung but rather tossed on the rack) and in the bathroom were dirty towels on the hangers. Obviously, this isn't a hotel and someone's real home, but I would have wished for the cleaning to be a little more thorough, and also for things like medication to not be standing in low open cupboards.
Overall, I would say this is an ok place for (young) people who want to visit Paris and be out and about a lot. We went as a family and I wouldn't recommend it as a place to stay with kids.