The apartment is exactly as described. It is spacious enough for four people, though in this case two of them will be using the kitchen/living room to sleep. The flat looks rather minimalist, but it is equipped with most of what one could need.
We stayed at the apartment in October 2016, when the weather was rather cool. The heating works perfectly well.
The apartment faces a street with numerous restaurants and it causes some noise from the outside. But with windows shut we experienced no trouble with it. On the contrary, muffled hum from the cafes brings in a certain ambiance!
The area is very lively, still quite safe. Lots of restaurants at the doorstep (including one with a Michelin star). Couple of supermarkets are within a 5 min walking range, as well as a Subway station. Notre Dame de Paris is as close as 10 min walk.
The owner of the apartment Mathilde was very responsive. She gave all proper instructions and immediately answered all our questions. It was a pleasure to deal with her!