I've seen a few airbnb spots in Florence and so far this one is the best in terms of value-for-money. If you are looking for something more than just a place to sleep it is a right address. It's classy and very well equipped. It can easily host 4 people (2 double bedrooms). There is a parking space in the backyard. Located 5min walking from tramvia that can take you to SMN station (7 stops) or shopping mall (2 stops). To reach historical center and zones of Santo Spirito and San Frediano I recommand bus no.6 which stops right next to the appartment. For coffe and pastry go to Caffe Imperiale (3min).
Just not to make this review too candy I must say that tv upstairs was broken and it was hard to get in touch with host (she was in India that time). I hope you are doing well Marina! See you!