Guido was a great host. He checked in on us periodically throughout our stay and gave us great restaurant recommendations too.

The apartment was as advertised - quick things to note:
-it's situated right between the two main train stations for Florence (Firenze SMN and Firenze Campo di Marte), so it's great if you have to use both stations during your stay
-it's roughly 20-25 min to either station, so either travel light or use wheeled luggage as it could be a bit of a trek with luggage
-there's no elevator and it's up a number of stairs as others have mentioned, but any averagely fit person will be fine
-there's quite a bit of noise from the nearby bars/restaurants on Fri/Sat but we're from NY so we slept without issue

Overall we would highly recommend Guido as a host and would visit again.