Pros
Nice, friendly, helpful and accommodating hosts.
Generous sized apartment with full kitchen.
Excellent location (this is our 6th trip to Florence and this was our favourite location)
Excellent water pressure and hot water temperature in the shower (something rare in Florence in my experience)
Cons
Can be noisy because apartment is on the first floor (but i think its hard to find a quiet place so close to the centre of town)
The shower leaked for us and the doors became a bit painful, getting stuck and coming off the rails.
The apartment above is being renovated and they start working at 8am, it woke us every morning. (The hosts obviously have no control over this)