This place is perfect! The hostess (Cecile) was very helpful, highly responsive and very nice. The apartment is super-cute and very comfortable. Everything that is necessary is there and everything was as indicated on the photos. The only thing is that it may be a bit smaller than it would seem from the photos but this is not a problem: it is still enough for 2 persons and in any case it is huge for Paris standards (or at least as far as my experience of affordable airb'n'b in this city goes). It was very clean and we were even offered towels! :)
The location is fantastic. The area is very pretty and close to numerous bars, restaurants and shops. It is central, very close to the lively Le Marais, and 3 minutes away from the nearest metro station.
I couldn't recommend this apartment enough. It is incredible, especially taking into account the price. Staying there was a really treat - if you have a chance, do not hesitate! :)