I've stayed with Enrica for 2 months, she was always available if any problems occured or questions popped up and is a very welcoming host.
The building is quite modern as is the apartment, which is comparably spacious and has higher celings than most other apartments in this area, the shower works well, the kitchen is fully equipt and the aircondition can also be used for heating, if you should visit in winter. It is situated in the San Frediano area, sourounded by lots of small restaurants and bars, about a 15-20 minute walk from the city center, as well as the train station and all well-known sights can be reached by foot from here as well.
I would recommend this apartment to anyone who would like to visit Florence.