Overall, it was excellent.
Location is great, less than 5 minutes from the train station, walkable distance from main points of interest in Florence.
Checkin was easy and quick, in person.
Place was clean, bed was firm and comfortable. To note, it is 2 single mattresses next to each other, but it was equivalent to a queen bed and it was not an issue. A/C worked well, which was critical with the summer heat. You can hear the tramways every couple of minutes, as they pass right in front of the AirBnB, but it did not bother us.
Shower was clogging a bit, but the hosts said they will fix it. Was not yet a real issue.