I stayed at Charlotte's studio in June 2013 with my mother and sister. The apartment is a bit crowded for 3, but ideal for 1 or 2 people. Jean-Luc, Charlotte's father, was very friendly and helpful, and recommended a list of good food places for us to try. I had some problems with the Internet connection at first but I sorted it out after awhile. My main gripe is that there is no door to the bathroom, only a thick curtain. Other than that, the apartment is very nicely decorated and quite charming.
The apartment is a leisurely 5 min stroll from the metro. Belleville is a very lovely neighbourhood - you can find practically everything you need in the shops around the area! I would stay here again - just with less than 2 other people! Thanks, Jean-Luc and Charlotte!