We loved Fabrice's place! He left us a thoughtful welcome gift and was very communicative both leading up to and during our stay. I especially loved the view of the Sacre Coeur from the bedroom.
The place is very close to the Metro (line 4), a 10-minute walk from Gare du Nord, which has trains to CDG, and a 10-minute walk from the Sacre Coeur / upper Montmartre area.
Note that it's 88 stairs to the apartment's door (and another set to get up to the bedroom). We didn't mind this at all, but keep this in mind while you pack!