Quentin's apartment is well-located in Montmartre, near many excellent shops and restaurants and bars. The living room is large and breezy, and the bedroom is sweet as well. The only things to note are that you must keep the windows open at night in order to remain comfortable during the summer, and this means that you'll hear the street noise quite clearly, so bring earplugs. Also, if you are sleeping more than two guests, the one in the living room will have to sneak through the bedroom at night in order to use the bathroom.
Beyond this, Quentin was extremely communicative and easy to reach, check in was simple and the apartment is in a safe location.