We loved Federico's apartment, it is very spacious and it offers every amenity listed: kitchen, fridge, sofa bed, and private access. The building had been recently renovated and it was immaculate. The location is optimal, equidistant from Duomo and Palazzo Vecchio, walking distance to restaurants and bars, I literally walked everywhere, including train station S. M. Novella.
Our host was waiting for us at the door as agreed. I strongly recommend this apartment if you are planning to stay in the heart of Firenze.