We spent few days in Domenico and Mario's guest house in Florence. The house is very nice and clean. The Old Mosaic room in which we stayed is very spacious and light, has beautiful old mosaic floor, private bathroom and a small terrace. The place is walking distance to the city centre but if you are tired of allday walking and sightseeing you may take a bus (the bus stop is 2 minutes walking). The house is equipped with shared kitchen which is great for preparing breakfast. There is some noise from the street, but apart from that it is a great place to stay.
Domenico and Mario are very nice and helpful hosts who do their job with attitude. If I came back, I would certainly consider staying there again.