The apartment is located in a quiet residential area, not far from the park of the Versailles Chateau. It is perfect for a family of four and manageable for a family of 6 (if Jean-Marie will accept you, as he did for us, maybe since we were there for more than 3 weeks). It is generally a very nice apartment, with toys and games, interesting decor, and nice furnishings. The location has its ups and downs. It's a 15-20 minute walk or so to the closest train station (Rive Droite), or you can use the B bus to get to the Chateau-Rive Gauche station (get off at Prefecture or Hotel de Ville) or Chantiers station. The B bus is also useful for shopping at the marché and Monoprix. That said, it's not a super convenient apartment for getting in and out of Paris with young kids because you then have a 35-minute ride into the city as well, but it can be done. It's not bad for enjoying Versailles. It is quiet and large enough for a family. If you have young children, there is also a small wooded public park very close by, with some playground equipment for young children (Parc Sémallé at the start of rue de l'Hermitage).
We had a few issues, like not knowing where/when to put out our trash and recyclables (even after asking) and having to deal with tiny, not very absorbent bath towels and a limited supply of cups/glasses. For the record, somewhere there are communal trash and recycling cans for the building (I never figured out where), but you can at least add your bags of trash and recycling to the communal cans when they are brought out to the corner in the evenings (Trash on Mon, Wed, Fri, Sat, and Recycling on Thurs). If there is no space in the cans, leave your bags next to the cans.
Overall a nice apartment, and Jean-Yves is very kind and punctual with check-in and check-out. It should be said that the apartment is not his own property. We spoke French with him.