Pluses: very clean, 15-20 mins walk from the historical centre, next to tram and bus, there's a fridge and aircon and other essentials, and the host was very communicative.
Negatives: the room is directly on a busy 3-lane road and even with windows closed the morning traffic woke us very early. There are 3 rooms in the apartment, each rented out as separate units. The halls and doors of the apartment are not designed for privacy, so you can hear toilet and sleeping noises from other rooms. The biggest shock was that when we could not sleep and asked to check out early, the host did not want to refund us the remaining nights. Overall the price is similar to many reasonable hotels in Florence but further from the centre.