We had a lovely stay here - Sébastien sent us great directions a few days before, the place itself was clean and well-equipped and Sébastien checked in with us mid-trip to make sure we had everything we needed.
The location is great - so close to the metro and Gare du Nord though the immediate area isn't that pretty you don't walk far to find great bars and cafes, and of course Sacre Coeur.
I would definitely recommend the apartment and Sébastien as a host!