I had a an excellent time staying with Jérémy and Quentin. First, this location is fantastic. The place is on l'Île Saint-Louis, basically an island in the middle of the Seine with beautiful views of Notre Dame. While you are in the dead center of action in Paris, l'Île Saint-Louis is quiet and peaceful. There are many bakeries, cafes, and bistros within 2 minutes walk. There are a number of Metro stations within 5-10 mins walk.
Second, the apartment is lovely. It's got everything you could need, and the wifi is snappy. The place is up one level, you'll need to take your bags up a flight of stairs.
Third, communicating was great; Jérémy helped me with all my questions and I had an easy time checking in and checking out.
I'll be back again, and hopefully I can book this place again.