Carlo's home is nicely redecorated and perfectly located in the heart of all of the key sites in Florence. It's a very comfortable home, nice bathroom, and comfortable bed.
As a host, Carlo was professional, courteous, efficient, and friendly. We were greeted with a welcoming smile and something to drink at the bar downstairs. Carlo helped us bring our bags up the stairs to the flat where we were treated with a bottle of wine and a thorough introduction to the city including maps, instructions, and tips. At departure, Carlo met us, again, and helped us get a cab and back to the train station.
I absolutely recommend Carlo for your stay.
Pro tip: You can walk from the train station to Carlo's flat. It's not a long walk, maybe 30 minutes. However, be aware the the sidewalks are narrow and the streets busy. Aside from that, everything was comfortably walkable all around the area. The cafe downstairs and the trattoria next door are both wonderful.