If this is available for your dates, don't think. Just book it. Amazing location. View from the balcony and living room is the Duomo. Great sunrises from the balcony. Walking distance to most sights. Good restaurants around.
The host is outstanding. Our best experience with Air BnB to date. Very helpful with planning our trip - where to see, where to eat, etc. Knowledgable and friendly. The house is spacious. Kitchen is small but very well equipped.
If I return to Florence, I will stay here.