When we booked the apartment, we knew this apartment did not have the best standard, but we were fine with it because we only planned on using the apartment for sleeping.
It had air condition, which was nice, and many pamphlets and books about Lyon that we borrowed during our stay. The host lived in the same building, which was practical. There are several city bike stations right next to the apartment.
HOWEVER: there are gray silverfish/long-tailed silverfish/Ctenolepisma longicaudata in the apartment. We did NOT know this, and when we let the host know, he did not reply.
It takes 30 minutes to walk to a he city center, and then you have to walk through a bad neighborhood. We chose to take a taxi back to the apartment after nightfall instead of walking through unsafe neighborhoods.
All in all, the apartment is totally fine for a couple of nights (except for the gray silverfish).