We stayed in Florian’s apartment for three days in early August. It was a great location and place for what we needed. Check in worked well with the codes he provided, no issues with that. Bed were comfy and water was hot. It’s a tiny place and located in a covered passage way among the shops so I would say perfect for a short term stay if you plan on just being there to lay your head for the night. There are things in the kitchen that you could use for cooking but it was missing some essentials like cups (only one we could find for the four of us) but we hadn’t planned on making any meals there and we didn’t spend much time there during the day. Because it’s small and covered (no actual outside windows), it’s a bit dark and there isn’t much ventilation so the downstairs bedroom has a bit of a musty smell. We found if we turned the air conditioner unit on for a while, it helped with that. It’s a bit of a hike to the Effiel Tower (about an hour) but we made a day of it and walked by Notre Dame and around the entire area, over to the Eiffel Tower and back. It worked well and we saw lots. We spent the next day in Versailles on a bike tour which I highly recommend.
We didn’t communicate with Florian during our stay, mostly because we didn’t need to and we had what we needed from him ahead of time. Overall, I would recommend the apartment for a 3-4 day stay but not sure if it would work well for a settled in long-term stay.