Federico's place is very nice and in a central location in Florence, making it very easy to walk to all the sites. The apartment was as described and shown in the pictures. The shower is quite small (somewhat typical for EU flats) making it hard for me (as a woman) to shave ;) Also, there is only one window so it is a bit dark even during the day. Since we were barely there during the day, it wasn't a big deal for us.
Our only issue was with check in. Overall, it worked out fine, but it wasn't the personal experience that many other reviews spoke of and so it left us somewhat disappointed. Despite messaging Federico of our planned arrival window, and sending several messages as we neared Florence, no one was waiting for us when we arrived. We ultimately waited 45 minutes before Federico's colleague Jose arrived to let us in. Jose spoke no English, so he rung Federico on the phone. We spoke with Federico for about 5 minutes and he did try to walk us through the features of the apartment but it was a little hard to hear and so I know we missed out on some things (in particular, we could never find the book with his recommendations that he mentioned - something that could have been easily resolved if he were there in person). Overall, we got the key and it was fine, its just that the check in process was not as we expected from other reviews.
Ultimately, I would recommend the property as it is comfortable, clean, and centrally located.