Good points: very responsive and helpful host, apartment right across the street from a supermarket and between two good restaurants, good base to walk (15-30 minutes) to main attractions in Florence.
Points to be aware of: as it's directly on the street and between restaurants, the place is noisy late at night and early morning (a challenge if you're a light sleeper). There is enough hot water for 3 people to shower, no more. Access to upper floor is through a narrow, steep staircase.