Alain's apartment was just perfect for me. It's right in the heart of Montmartre and was incredibly easy to venture from. The neighborhood is very navigable and close to multiple public transit stations, as well as walking distance from some of Paris' great sights to see. The apartment itself is a cozy and quiet studio that, for a solo traveller, was just what I needed to come back to after a day of wandering.
I didn't get to meet Alain personally, but he was very communicative and helpful, and his friend Omar who brought me the keys was extremely kind in showing me the tips of the apartment.
I had an excellent stay in Paris. If you're visiting, absolutely consider this option to stay!