Only negatives: it is within the limited traffic zone, so arriving by car is impossible. We returned the rented car at Locauto that is only 500m away, but it was a lot of work to walk those blocks with a 3-year old kid and also the heavy bags. And the staircase is VERY difficult because it is on the third floor with high ceilings, so I would not recommend for people with locomotion difficulties.
Staying at Bellevue House was a good experience. The attendance of Mr. Luciano and Alessandro was extremely friendly and kind, both on prior e-mails and personally.
The room ("Ginevra") is huge, tasteful, with windows that really isolate light and street noise. The bathroom is narrow but functional and modern, great shower. Everything was spotless. There was a double bed for us and another, lower but equally big for our son. Air conditioning and the fridge were great. A free large bottle of mineral water was provided daily (despite the tap water is perfectly drinkable).
The location is great for walking around the historic center, churches and museums. It is also very easy to use the train station.
They do not serve breakfast in the morning but indicate neighboring cafes. In fact, all their indications of restaurants are precious, enjoy!
Moreover, fantastic! Grazie mille!