We stayed for 9 nights --
PROS:
(1) This apartment is in a great location, the neighborhood is nice with lots of markets, shops and little restaurants down the street. It felt like a safe neighborhood. The Jules Joffrin Metro stop is just steps away, and Sacre Coeur is visible from the apartment and within waking distance.
(2) It was comfortable for us -- 4 adults and 1 child. Sleeping space for max of 7 includes 2 people on each of 2 double beds, 2 people on the futon and 1 on the (non pull-out) couch. There is one WC (like a small closet with just a toilet, no sink) and a bathroom with a sink and tub with a low hand-held shower head.
(3) The kitchen was stocked with dishes, cups etc, and the layout with nice since it was open with the living room, dining area and bar stools.
(4) The laundry washer/dryer machine worked.
(5) The elevator, although small (it fits 2 people comfortably) was convenient, although it was not working for 2 days of our stay.
(6) The wifi access was convenient. It was not working for 1-2 days, and the owner was responsive and came back twice to check it out (it just needed to be switched off then on again and it worked fine for the rest of our stay).
(7) The building was VERY quiet -- it almost seemed as if we were the only people there!
CONS: The apartment was not clean. The floors were very dusty/dirty when we arrived. There were many potted plants which were nice, but they were all dusty and had cobwebs on them. There was an ant problem on the kitchen counter as well. There was also an abundance of moths in the apartment even though we always kept the windows shut in the evening. A glass in the cabinet was broken, and some of the glasses/dishes seemed less than clean. The fabric shower curtain was stained orange-brown at the bottom due to mold. I would give it 4 stars if the apartment were clean.