The main problem for me was the mattress where I slept. It is not about being soft or hard, it has a weird hard plastic feel structure beneath the first thin textile layer. This makes it so uncomfortable that I was tossing around with pain in my shoulders, and I only weigh 70Kgs.
The host acted surprised when I told him, and by his answer one can assume he won't change anything.
About the location, there was nothing special around the apartment, the shops nearby were not interesting. Better to stay in an area like Croix Rousse.