This was my first time in Florence, staying 2 nights in Carmine's apartment. I loved the location! I arrived late to Florence by train and the apartment was very close and the instructions provided were very helpful with the pictures. The room I had was right above the market so it was a bit noisy but you should have no problems sleeping with earplugs. It was extremely spacious and clean! The website Carmine provides is great if you don't have concrete plans coming here. I did not get to meet Carmine but there were no problems. One thing is that when I was here, the room/house was quite cold at night. The heater was on the first night but I noticed when I got back the second night it was quite cold. However I only had that night left so I just dealt with it--I'm sure if I contacted Carmine it would have been sorted out.
The bathroom is clean and has a washing machine; there is a large kitchen (however I did not use that). Would recommend!