We stayed for 5 nights. This apartment is consistent with what you read in the description and see in the photos. Connecting with Guido when we arrived was problem-free; however, we had a mobile phone with us.
Highlights: Large size of apartment, proximity to attractions, the patio with its view of the Arno, Guido's attentiveness to our needs.
Watch out for: on the 5th floor (many stairs, challenging if your luggage is heavy); shower temperature is not consistent, but you can tell when the temp is gong to change. (Guido did his best to try to fix it but I believe it was beyond his control.) Earplugs are helpful if you want to sleep with the windows open, since you are in the city!
I would recommend this to others!