We (2 adults, 2 children ages 11 & 14) stayed for 6 nights in June 2018. I found the apartment exactly how described: good space for a family, conveniently located (near shops, grocery stores, restaurants and close to the metro & only 3 stops from the Invalides metro stop!), and a quiet courtyard (loved that we didn't hear traffic!). I agree with a couple of reviews which referenced that there are a couple of places which show a little wear, especially the bathroom. But the place is SO clean. I thought it met all of our needs and that it was a great value. No complaints at all.
The beds were very firm; we found this to be consistent with our stay in France. We had stayed in 4 hotels and all the beds were very firm. The pull-out bed didn't feel any different than the other beds we had slept in. My children said said the bunkbeds were firm, but fine. I noticed that there was a pack n play for those with infants - there was definitely room for it.
We were worried about the temperature in the apartment - during our visit the high ranged from 70 degrees to 84. However, the ceilings are high and the cross ventilation from the different rooms, keeps it very comfortable. The last night (the hottest night), the concierge brought us a fan. My husband really appreciated it, although the temperature was actually ok.
The washing machine works very well. There is no clothes dryer, but there is a rack to hang dry and this worked fine. The kitchen is a little small for fancy cooking-- but seems equipped with the essentials. We had breakfast and had take-out food (from a local pizzeria and Chinese place) and found it completely satisfactory.
The host is exceptionally responsive and helpful and the concierge is very friendly and nice (limited English though). I booked this 6 months in advance and feel lucky to have found it.