Our family of 5 (adult children) enjoyed the apartment very much. There are three sets of French doors that open up to the patio. The patio "made" the place and enlarged the space. We sat out and had wine every afternoon/evening when taking a break. It is an excellent location for sightseeing. It was also nice to have not one, but TWO clothes washing machines. We used them with 5 people. We all thought the beds and pillows were very, very comfortable - even the sofa bed my 6'4" son used.
The owner does an excellent job explaining what to expect at the apartment. We loved it and the host was perfect. He made sure the nice cleaning lady greeted us when he could not make it, and offered some flexibility with checkout time. The upper bedroom IS sloped. It is indicated in the listing, but just note it. -And same with the stairs. There are LOTS of them. This is not for everyone. If you don't mind staying in something more "real" than a hotel, it is wonderful. We loved it and would book it again if we returned to Paris.