If you are looking for a central place to stay in Florence/Firenze, you won't find anywhere closer than Ulisse's place. Literally 1/2 block from the Duomo, it's the perfect place to stay to explore all that the city has to offer.
Ulisse was an amazing host, very friendly and helpful. You cannot bring/drive your car within the pedestrianized town center before 4:30pm, so Ulisse let us have his parking spot (not reserved) just outside the zone, and then drove me the 1.5km back to the flat.
There is a taxi stand 30m from your front door though, and everything is walkable so there's really no need for a car anyhow.
The two bedrooms (master with a queen & kids with two singles) were perfect for our family of four.
The flat is on the fourth floor but there is an elevator if you want (we only used it for the luggage)