Jean-Pierre is the sort of host, and his apartment the sort of place, that you'd expect AirBnB to feature in a commercial. For those just looking for a quick take: stay here - enjoy a great base for exploring the city, spend time in an awesome apartment, and befriend an incredible man.
Jean-Pierre was extremely flexible about our arrival time and made sure he was there to greet us, introduce himself, and explain how things worked. His English and French were both quite good, and we found ourselves conversing in one language as much as the other - communication was excellent.
We had the upper room, which was overall more than satisfactory. The area was clean, the linens freshly washed, and soap/hand towels/earplugs provided. The bed was comfortable and more than large enough for two; additionally, the wifi router in the room and accompanying desk made scouring the Internet for things to do and places to eat in Lyon very easy and fast. The only complaints we had were that the room was not very well lit (half a dozen soft light fixtures and one floor-level window) and that the ceiling was quite low (probably around 1.75m/5'10"). However, as we only spent time in the room to sleep at night, these were minor inconveniences.
The apartment itself is fantastic - it is decorated with black and white photos of actors, vintage Star Wars, Star Trek, Alien, and other movie posters, tons of books, and Jean-Pierre's collection of bass guitars. The living room also boasts leather couches and chairs and a projector-screen-speaker setup that turn the place into a private theater. The kitchen is also equipped with modern appliances to match the overall aesthetic of the apartment. The best thing about this place, though, is Jean-Pierre himself; despite reading the other rave reviews, we were surprised at how personable, accommodating, and knowledgeable he was. In addition to making breakfast for us our first morning, he took time to give tips about Lyon and discuss everything from movies to his time playing in a band to cultural differences to politics (although never going out of his way to engage us in conversation against or beyond our desire). We also got to chat with guests staying in the other room and compare travel experiences, exchanging recommendations. While I use most AirBnB places as merely a place to sleep between exploration, this was the first that actually tempted me to just stay and hang out; between the awesome space and Jean-Pierre himself, it's almost worth the trip from Geneva to Lyon just for that. We hope to return soon!
TL;DR: Upper room does not get a lot of light and has a low ceiling, but does have a comfortable bed, private sink and mirror, and is otherwise more than satisfactory. The apartment and Jean-Pierre are both great and almost worth the trip alone.