Clement's apartment is awesome. We were traveling with a 10-month old, so we wanted to avoid tons of stairs. Clement's flat is only up one flight of stairs, which made things very easy. It's on a great, quiet street close to many sites and several metro stops. It's about a 20 minute walk to the Seine, so we pretty much walked everywhere. There are tons of restaurants and grocery stores nearby. Also, if you're looking to take a break from traditional French cuisine, we highly recommend Happy Nouilles (they actually make the noodles in the front window so you can watch) for some amazing takeaway.
The living space is huge, and the kitchen is very clean and modern. The bedroom is smaller, but also extremely quiet. There is also a portable crib available, which we took advantage of for our 10-month old daughter to sleep in. We loved our stay!