5 out of 5 stars!
The location is perfect. Our first night we walked the 8 blocks to the Eiffel tower. You can buy beer or wine from the wandering vendors in the Champs du Mars park to relax and watch the lights on the tower, in the summer the display starts at 10 PM. The next morning we walked 2 blocks to pick up hot quiche and pastries at the Maison Othon for a quick breakfast in the apartment, then 5 blocks to the pedestrian-only market area of the Rue Cler to stock up for picnicking (cherries, a half size bottle of Rose, Comte cheese, salami, baguettes). There are multiple small grocery stores and restaurants within the block, we highly recommend I Pupi for pizza just across the street and Yookoso Sushi half a block down. Maison Chaudun across the street makes both chocolate art and extremely good 'paves', which can be kept in the apartment refrigerator.
The owner Marc is very attentive and has a good team. Despite our limited French we had no trouble communicating with Louisa (the housekeeper) and Paul (the taxi driver who picks you up at the airport). The few small problems we had (leaving our room key behind while out to dinner, needing to replace the room fan) were immediately fixed, although we were glad we had local phone/text coverage and the numbers when we locked ourselves out. :)
The room is a great value, although there are some limitations. My wife and I traveled with our 16-year old son, and the apartment is small for three people over more than a week. The living room is also the bedroom, with a queen sized elevator bed for the two parents and a couch for the teenager, so everyone has to agree when it's time to get up and switch configurations. Also, there is no air conditioning, which could be a concern on the very hot days (we had two days of 40 degree Celsius). We dealt with it by wetting our travel blankets and using usb travel fans in addition to the room fan to keep the air moving, as well as religiously shutting the aluminum blind to the window overlooking the quiet garden during the afternoon.