If I were returning to Florence, I wouldn't even hesitate - I'd definitely stay here again.
The apartment would be a good size for someone traveling alone, or a couple (I believe the bed is a queen). It's exactly as the pictures represent it (and impeccably clean).
The location is perfect. You're a short walk from all of the major landmarks. I used to live in Florence - this is exactly where you'd want to stay.
Alessandro and Azadeh were just what you'd hope for in a host: helpful and responsive.