I brought my three daughters to Paris for a graduation celebration, and we loved our stay at Sebastien's apartment. The location was wonderful: the neighborhood is vibrant, not touristy, with lots of restaurants, grocery stores, bakeries and everything else one might need. It was also very walkable to many sites in Paris such as Notre Dame--and the Metro and bus stops were right near by when we didn't want to walk. There was enough space for the four of us (two daughters shared the king size bed comfortably), including enough space for each to go off and have some private time if needed. It was very quiet and restful, a lovely place to come to at the end of the day (the rooftop garden was a nice plus). While having the toilet off the kitchen was a little strange, I didn't mind; it actually was useful to have the toilet, shower and sink/mirror in three separate spaces with four people.
Sebastien truly was an amazing host. He responded very quickly via the app to any question or concern, was there to greet us when we arrived, helped facilitate our last day--even waited with us to be sure we got into a cab to the airport. He was extremely pleasant, kind and gracious. I can't recommend him and the apartment highly enough.