Marco’s apartment was lovely. It’s in the most amazing location, directly under the duomo! It is also very easy walking distance from the central train station- even with a suitcase (only about 12 minutes walking. Very easy to find.) I was only there for one night. It was very comfortable, and well stocked with soap/shampoo, and kitchen supplies (even police oil, spices, sugar… etc.) I did not cook, but the kitchen was nice. The AC was nice, as someone who is not used to the heat!
It was mostly quiet, however lots of screaming/singing/general raucous in the middle of the night (maybe 2am?) but that is just what you get when you stay in the center of the city.
The only negative thing was a funny smell. I’m not sure if it came from the bathroom or the AC. It was tolerable, but started getting annoying on my 2nd day. As I mentioned I was only there for 1 night, so it didn’t bother me too much- but I think it would have had I stayed longer. There may not be anything that can be done about it- maybe this is just how old buildings in Florence smell.
Overall, a wonderful stay.