Communication and Check in was super easy. Fabien and Rachael were nice enough to let us check in way earlier than stated here, right after our train arrived and always answered our questions very quickly.
The location is perfect and as described. We walked only a short time from Gare du Nord, Metro to the city centre is also close by.
The flat is spacious, especially for Paris, and has everything you normally need.
In total, we had a great stay and I can highly recommend staying in the flat of Fabien and Rachael.