Raul is a great host, very reactive and available, he will give you good tips. The flat has everything you need for your stay. Some mentioned the lack of mobile signal/wi-fi in the bedroom (basement) but I'm pretty sure it's a good thing if you come to Florence for a romantic holiday ;) Upstairs the internet works perfectly.
The location is perfect with great bakery, restaurants and bars nearby and we could visit the whole city on foot.
You may hear a little bit of noise from the neighbours as it's an old building but I guess it all depends on what you are accustomed to, and old building means charm :)