My family (wife, 8YO and 10YO) stayed at Richard's place for 5 nights. The size of the flat was just right for our group and far more comfortable than a hotel. Richard met us upon arrival and we explained everything about the apartment and made recommendations for shopping, restaurants etc. He is super, interesting man and we enjoyed getting to know him.
The location is awesome. The church across the street is beautiful and the flat looks right out to the gargoyles which my kids loved. The Louvre is about 200 meters away as is the Seine. We were able to walk to many of the beautiful Parisian sights (Notre Dame, Saint Chapelle, Musse D'Orsay, Musee Pompidou, Luxembourg Gardens, Place de la Concorde) and take Uber for about 15 Euro to some places that were a bit too far for the kids to walk (Eiffel Tower and Sacre Coeur).
There are great paths along the river for running which are beautiful and FULL of people hanging out with friends.
Finally, having a washing machine in the flat was great so that we could pack a bit lighter and have clean clothes (we visited other cities as well on the same trip).
Great place, super host.