The apartment is fine for a family with two children. The system to collect the keys and return them is quite easy. There is room with a double bed and the couch in the living room can very easily be pulled out into another double bed and can also be very easily folded back again. The toilet is in a separate room from the sink -as usual in paris-. The whole apartment was very clean. The owner had left a sheet of paper with useful information and telephone numbers -although taxi companies do not always answer the phone-. The wifi worked fine as well.
The apartment is on a 2nd floor without a lift, just next to the lamarck-caulaincourt metro station, from which it is rather fast to go to the city centre. It is also at walking distance from the sacré coeur.