I can only recommend this apartment. I was here in Firenze to attend a language school, and the apartment had all the equipment I needed and it was nice and clean. Marta was very quick to respond on every message (also in English), and was kind to ask how things were going during my stay. Check-in went perfectly. Unfortunately, I had to leave the Italy before time because of the situation of corona-virus, and Marta was kind to ask if I needed help with anything.
The location is perfect, in the historical part of the city, just next to Palazzo Pitti, and in walking distance to many other turist attractions, shops, and restaurants.
The only down side was that it was sometimes difficult to regulate the temperature of the water, so it was either very warm or very cold. But this was a minor issue. The water also contained a lot of chlorine, which affected the taste, so I preferred to drink bottled water.