My 3 Friends and I stayed at Estelle's apartment for 6 days. The apartment was just like it seems in the pictures. Small, but very bright and in a great neighbourhood. We were able to easily access the metro from the apartment, and there were lots of great markets and shops nearby too. It was also well equipped with all the necessities.
I did not meet Estelle, but Fred met us at the apartment to drop off more towels and showed us how to reset the water tank if we had any problems.
We did find it very warm in the apartment while sleeping because of the skylights in both sleeping areas, but it probably wouldn't be a problem most of the year (we were in Paris during a very hot and sunny week in July).
Overall, Estelle was an excellent host. She was easy to contact and quickly replied to any questions I had. I would recommend her apartment to anyone looking to stay in a nice quiet area of Paris.