I stayed with my sister and two teenage children. We had a delightful week in this apartment, during a very hot week in August.
Plus points: The flat was well equipped, location was fab, the apartment was just delightful. If you go on the balcony and stand on tip toe you can see the Eiffel Tower. Comfortable beds. Lots of stairs (good exercise). Building felt safe.
Problematic points: We were given one key and that was between four of us. There is high security in the building (a good thing) which means there is an entrance code then the key has a magnet to open a door to the stairs. Having one key limited our ability to get out and about. I tried to contact the person who was to let us in (not host) but there was no response so we ended up just managing.
The loft bed is really for one not two as a heavy beam sits over half the bed meaning that you would be lying with it inches from your face, so not for the faint hearted.
I have scored lower in a couple of areas for the sake of honesty but overall we did have a lovely time and the apartment suited our needs very well.