My fiancé and I had a wonderful stay at Francesca's lovely apartment. One of the best things for us was the proximity of the flat to everything, the Duomo, Ponte Vecchio etc. Coming from London where everything is a bus or train ride away it was a lovely break being able to walk to everything we needed. On arrival we were even given a map pointing out the nearest supermarket, a good pizzeria and other practical places close by.
The apartment was very clean and had all the amenities you would need for a prolonged stay, we were particularly impressed by the strength and reliability of the wifi connection.
It was very hot during our stay, but with the windows open and fan on it didn't disrupt our sleep. Francesca offered us a brand new air conditioning unit for a small surcharge per day, which is reasonable considering how much electricity they pull, so if the heat was a problem that is another great option available to you.
Overall we couldn't have been happier with our stay and will definitely be coming back in the future. Florence is a beautiful city, we even found the perfect engagement ring here. We recommend you try out this apartment and fall in love with the city as we did.