We enjoyed our stay overall, but would likely stay outside of city center if we came back to Firenze. The apartment was clean and spacious. The bed in the master bedroom was very comfortable. The air conditioning was gloriously cold after walking around all day in the hot summer!
The plumbing must be older, as the water was not hot in one of the bathrooms and only hot about 3/4 of the time in the other, which made showering difficult (for 4 people). There was also a sewage smell coming from the pipes, similar to what you will smell walking around the city center streets.
I strongly recommend NOT driving and parking a car. The city center streets are not made for driving. It was terrible trying to drive through massive swarms of pedestrians and finding a car garage that ended up being €31 per day.