We (two adults, mid-40's) spent 10 days in Laurent's apartment and would enjoy staying there again.
Check-in and out was easy. Laurent provided all the information we'd need ahead of time, even texting the day we flew in to let us know we could arrive earlier than our scheduled check-in if we'd like. He gave us a quick introduction to the apartment and was very kind to leave us with a bottle of wine (which we enjoyed on the balcony one evening, alongside a fantastic roasted chicken we bought from a nearby butcher shop).
While the photos in the listing are beautiful, the apartment is even better in person: beautifully decorated, light and bright with gorgeous windows, high ceilings, spacious, and comfortable. The balcony is small, but perfect for two people.
We found the neighborhood convenient for transportation, via the bus or Metro. (We found the Rue de la Pompe Metro station most convenient, but depending on where we were going, used neighborhood bus stops just as often.) There were two grocery stores within easy walking distance, many restaurants, even a coffee shop. (The walk from the apartment, through Place de Mexico, and on to the Trocadero was especially pretty - about a 15 minute stroll from the apartment for us.) We also enjoyed the easy walk to Bois de Boulogne.
There was not a hairdryer (or if there was one, we didn't see it), so keep that in mind if you need one.