I was very pleased with staying at Flavia's apartment. The flat is nice, cosy, very clean and well-equipped (kitchen, etc). Location is also very good, short walk from historical places (5-10 mins from Basilica Santa Croce, about 15 min from Duomo), but quiet area. Two rooms are at a quite large distance from each other (separated by a kitchen and a nice living-room) so sharing the flat with other travelers is comfortable. Flavia herself is a very pleasant host, and she speaks good English. Actually, I didn't expect so good accommodation at such low price. This would be my choice if I decided to live a longer period of time in Florence - say, a month or more - because it's a very comfortable place and I felt at home there.
Thank you very much Flavia!