I stayed in the apartment for 9 weeks during the summer of 2017 and it has been a wonderful place to stay in all regards. The apartment is extremely clean and, in addition, I did not see even one bug the entire time I was there! The apartment is located in a fabulous area (the heart of the 6e arrondissement) and is equipped with all the basics except for a washing machine and an oven (there is a microwave, tea kettle, stove top and fan).
It is located on a street full of bistros, 5 min to Marks & Spencer's groceries and 7 minutes to 2 different metro lines. It is located between St-Sulpice church and St-Germain des Prés and you are near Odeon and all the famous French cafés (Procope, Café de Flore). It is also close to the cheapest and probably biggest pharmacy in Paris.
The apartment itself does not give on the street but on an interior light well which is less interesting perhaps than a view on the street but has its advantages: because it does not have too much direct sunlight it does not get too hot and also since it does not give on the street, it is surprisingly quiet (although on Friday and Saturday nights you do hear the hum from some of the bars around which I found rather pleasant.)
The windows are large and open easily (although just one side opens). The apartment is pretty with high ceilings and beams and the thick walls that must date back a century contribute to maintain a surprisingly comfortable temperature even in extremely hot weather. The bed is exceptionally large and comfortable and the bedding soft and nice quality. The tv works great as well as the internet. Please note that, as for many Parisian apartments, it does not have an elevator and it is located on a third floor.
Overall, the apartment is spacious, safe, and located in a wonderful area. The host, Jacques was very nice and responsive to any query or need. I enjoyed my stay tremendously and recommend highly this hidden gem.