Overall, we had a nice stay at Arnaud's place - he was prompt to reply and helpful, and the apartment is beautiful and well located. There were some issues though:
There were mice in the apartment. We told Arnaud about this and he replied "typical for Lyon", and didn't offer any solutions.
The hot water ran out after 2 minutes every day in the shower. For two of us, this was incredibly frustrating as we'd then have to wait an hour for more hot water, or the second person would have to brace a cold shower.