This is a wonderful find!
People: Giacomo is warm and communicative. He met us at his home and gave us clear instructions for how to operate the place. He is trustworthy and kind.
Place: The ceilings can be short in some spots but the whole place is essentially normal. My 6'6" brother may have trouble with the hallway to bedroom transition, but 5'8" me was very OK. Shower and restroom are clean and without trouble. We made bare use of the kitchen and it seems very serviceable. The bedrooms are spacious and quite comfortable. The whole place is quiet and easy to sleep in. Easily one of the best apartments I have visited.
Location: Oh, God. This is a great location. You are a street away from Palazzo Pitti and it's quiet but close to great late night food and only a 15 minute walk from the Duomo. This place is super convenient.
Final Call: No reason to avoid this place unless you are NBA height. The host is a truly good person, the place is hard to fight with, and the location is perfect. Have fun!