We absolutely LOVED the convenient location of Melissa's place. It is right next to 2 RER lines (1 direct from CDG airport so no need for a taxi) and multiple metro lines. The shop owners on the busy street below were all so kind, and only a 2 minute walk scores a view of Notre Dame (5 minutes to be at its plaza). The apartment is perfectly outfitted for guests included a nicely stocked kitchen, washer/dryer, and nice sized bathroom. It was bigger than any hotel room I have ever stayed at in Paris.
It is, indeed, quite noisy (as many reviews have mentioned) if you go to sleep early. We found that after walking all day it wasn't hard to sleep (although usually up late).
A manager met us in front of the building to provide a key and all the personal instructions needed.