My wife and I spent a a very enjoyable though all too brief stay (1 night ) as we had planned only that much for the Florence part of our trip. Alessia is a very gracious host, and she made sure we had everything we needed. The apartment is quite lovely and is well located near everything of interest in the center of the city.
One tip. If you rent Alessia's place partly because of the garage, make sure you are driving a compact or sub-compact car. Via di Mezzo is a very narrow street, and if any cars are parked across the street, the radius you have for turning into the garage is quite small.
You would do well staying in Alessia's place.