Guillaume's place is very well located in Montmartre. It is located in a small quiet street but only few steps from cafes, restaurants, pharmacy, anything you actually need to enjoy your stay. It is very close to the metro station Blanche, and the Moulin Rouge.
We enjoyed easy access to apartment on the ground floor, very quiet and spacious enough space and amenity just needed to relax and have a good night sleep. Additionally apartment was fresh enough, even without A/C, during the pick heat Paris had when we were there.
We really recommend Guillaume's place, he is the perfect host, if you want to enjoy Montmartre like a Parisien.