My friend and I stayed over at Charles' apartment for two nights while in Paris in the summer. We chose it specifically because of the Montmartre location - although this area was a tad removed from the quaint villagy feel of Montmartre, per se, just by a 20 minute walk though; you want something around Abbesses if that's what you're looking for. Getting to the apartment from the metro station was really straightforward. I would suggest you get to the apartment from the Marcadet-Poissoners station and not Chateau du Rouge, which we found a bit dodgy although it is a tiny bit closer to the place.

No reflection on the host or the home though! :) The apartment perfectly met, if not exceeded, my expectations. The space was just right for 2, very clean and very comfortable, looks better than the pictures! - heck it even matched my personal aesthetic. Charles was friendly and accommodating - and not just because he left us chocolate - there was also useful information on getting around, the number to call a taxi, etc., (LOVED the pocket map - thank you!). All in all, a great stay. I would certainly recommend it!