This is a great flat with a lot of character. It's also huge, with a cool "nest"-like loft bed in addition to the main double bed on the ground floor. The location is unbeatable, literally across from the Accademia Gallery and 3 minutes down the street from the Duomo. But it wasn't too noisy at night, because the museum closes around 6pm and after that the street is fairly quiet.
Luca was very communicative on WhatsApp before and during my stay and was able to provide lots of helpful recommendations for Florence. It was very hot when I visited, but the ceiling fan was actually quite helpful in cooling the bedroom area down.
The only thing to note is that the wifi is very slow, but this shouldn't be a problem if you're out exploring most of the day.