I had a great stay at Lucille's apartment. The apartment was comfortable and nicely furnished. It's a single room apartment so the bed is the sofa bed in the living room / kitchen. This was very comfortable, and there are plenty of fans to keep things cool when it's hot. There's also a washing machine available to use which is handy.
In terms of location, Bel-Air's a nice area. It's very chilled and not too far from Bois de Vincennes if you're into walking/running. Metro doesn't take too long from there to get into town.
Lucille was a great host. She made sure I had a good stay in her apartment, and she worked around me when it came to check in/check out times.
I stayed for a little over a week, and I would definitely stay here again if I'm back in Paris.