We stayed 7 days in Paolo's apartment and we had a wonderful time there.
Paolo is a great host, he waited for us as we arrived later than planned.
On our arrival Paolo gave us a map, advices on places to visit in Firenze and where to eat in the neighbourhood.
The room is spacious, with a high ceiling, clean, quiet, all the amenities to cook are provided and there is a little private backyard where you can smoke and let dry your clothes. In our opinions the pictures doesn't give enough credit to the flat.
He is located in a cool neighbourhood, with plenty of restaurants and cafes, where you can feel almost like a local (especially in the morning), and it takes only 10mn walk to reach the Ponte Vecchio, 15 mn for the Uffizi and 20/25mn for the Duomo, Galleria dell Academia or the train station (Santa Maria Novella). And the bus stop is not far away neither (2mn walk).
Next time in Firenze we will definitely choose Paolo's flat again.
A little advice, if you're coming from Pisa airport by train make sure you check the time of arrival cos some train take longer than others, for example with the train at 4:20 PM (16h20) it took us 2 hours to go to Firenze instead of the usual 1h.