If you have the chance to stay in Isabelle's appartement: Do it! You won't regret it. Just minutes away from Mont Matre (with a wonderful view on Sacre Coeur from the balcony) it's the perfect place to start discovering Paris. It was very nice, tidy and comfortable. We didn't meet Isabelle in person, but she perfectly organized the key transfer and was always reachable, if any problems would show up (what they didn't). Best host imaginable! Thanks for letting us stay at your place, Isabelle! :)