The apartment is in a great location within the historical core (18 min to Accademia, 5 min to Uffizi, 20 min to SMN train station) which offered respite in hot sightseeing days. All of the essentials are provided, including thoughtful touches like laundry detergent and an umbrella for rain. Although I didn't get a chance to meet Guido, he was super helpful and responsive by e-mail. He also had the best restaurant recommendations! Mr. Lombardi on the ground floor kept watch over us to ensure we knew how to work the locks (Medieval building), have appropriate gear for the weather, etc. I felt extra safe! I only wish I knew what he was saying ;-)
A few tips:
1) The apartment is about 1400m from the train station, so it's best to take a taxi to/from the train station, especially if you have large suitcases like we did (9 to 15 euros depending on traffic).
2) There is a taxi stand at Piazza Santa Croce, so it's super convenient to get taxi without having to call (2 min walk).
3) The apartment is located on floor 2 (which is 3rd floor for Americans), so getting luggages up and down were the biggest workout of our trip (maybe it's a tie with climbing the dome then campanile at the Duomo).
4) There are 2 supermarkets nearby (10 min walk).
5) Sleep with the A/C on and windows closed, so won't hear the street noise below.