The beautiful pictures on the listing do not do this apartment justice. It is a polished and sophisticated space in a beautiful (and beautifully maintained) historic building. The intelligent layout is perfect for two couples, as we were, but would work well for a family. Everything that tends to be a source of frustration in overseas rentals works (Wi-Fi, English language TV stations, washing machine - a first for us in Europe!).
The apartment's placement on the ground floor has two big advantages - no stairs at the end of a long day of sightseeing, and huge outdoor terrace space that belongs to this apartment alone. We ate all of our dinners there, and made good use of the separate, covered lounging area. The location is perfect too - across the square from the church offering nightly Puccini concerts, and less than a 10 minute walk to any site within the walls. The host, Sonia, is delightful and ready to help with anything you need.
Two tips - finding free parking outside the walls simply isn't worth the trouble. Park at the Carducci lot a 10 minute walk from the apartment, feed the meter 5 euros at 8:00 AM, and you are good for the next 24 hours. Also, for stock-up supermarket shopping, go outside the walls. There is an Esselunga not far behind the trainstation. Daily shopping within the walls is easy after you've gotten that out of the way.