We had a great stay in Alessandro & Azadeh's apartment. While the apartment is small, it is quite comfortable with some great amenities like an elevator, kitchen, large bathroom, washing machine and small terrace with a great view of the Duomo.
Azadeh greeted us when we arrived and gave us a very helpful introduction to the unit as well as many tips for things to see and places to eat while we were in town. She also helped us make restaurant reservations and booked a taxi for us, which really made our trip. I would definitely recommend staying in this unit if you're looking for a comfortable, central home base for a stay in Florence.