Guido's place is perfect for a short or long stay in Florence. It's very simple to get to from the airport (via taxi) or from the train station (we walked).
The apartment is in a perfect location -every major tourist site is walkable but it's on a quiet enough street that you won't feel bombarded by noisy tourists.
The apartment is also very safe!
Guido was communicative and helpful, he even had a very handy guide of the neighborhood in the apartment. We came during the summer and the AC worked like a charm, we were 100% comfortable the entire time. I highly recommend Guido's place if you're thinking about visiting Florence - we will definitely be back!