First of all Location, Location, Location! If I was to drop a pin on a map for where I would want to stay in Florence it would land on Allesandro's flat. Convenient to everything but on a small enough street that there is no traffic or crowd noise.
Secondly, Alessandro was amazing. So accommodating to our changing schedule and helpful with recommendations. He was even willing to make a reservation at a restaurant we wanted to try but could not contact ourselves. He welcomed us with a bottle of wine and even had fresh milk in the fridge for coffee.
Finally, the flat. Wonderful and well kept flat with all the amenities you could need. Plenty of room and comfortable beds.