We really enjoyed our stay, the apartment is neat and quiet as it is located on the ground floor of a building courtyard (and not directly on a street). The downside is that it is a bit dark during the day, but as we spent most of the day outside it was not an issue.
The location is just great ! Close to the Luxembourg gardens, and boulevard Saint Germain. There are also many restaurants and cafes close-by. Charles, the host, was very helpful when we talked over the phone.