We visited Florence in September and we stayed at Guido's place for 5 nights. Guido is a very welcoming host. He answered all the messages quickly, met us near the apartment and brought a blanket and bed sheets for the sofa. He also offered a city map with all the most important things marked on it. Also, he booked a taxi for us at the day of departure.
The apartment itself is very conveniently located and equipped with everything what is needed for a comfortable stay. There is a supermarket nearby and all the tourist attractions are within 15 minutes by feet.

I highly recommend Guido's place.