We had a great time at Rossi apartment: very well located, clean, nicely decorated. Eleonora welcomed us and she was really nice, giving us a lot of tips for our stay in Florence.
The only thing I found sad was about the hidden prices for the reservation. You need to know that you will have to pay cleaning fees in addition to your booking and if you arrive after 8pm you have to pay 20euros extra. I would suggest to make this very clear in the advert.