My stay at Carolina's was very pleasant. I was greeted by Laura (Carolina's mother, I believe), who showed me around and gave me the keys. The place was very clean and quiet.
The flat location was right in the heart of Florence, and very close to Il Duomo, Piazza Vecchio, the Uffizi Museum, and the Accademia Gallery, Ponte Vecchio, and many of the other popular destinations in Florence.
I would definitely stay here again.