The apartment is great - very centrally located, not far from public transport, walkable distance from all the sights. It also has 2 separate bedrooms and bathrooms & definitely enough space for 4 people staying together. Chiara is very communicative and arranged everything perfectly; we even had an UK adapter. The flat has all the needed amenities - kitchen with right tools and needed things for cooking. It was a great stay!
The only tip is not to eat in restaurants as the places around the flat are quite expensive due to popular location. There is a local supermarket, which is on one side of the fountain 5 minutes from the flat, called Pam Local.
There is no lift and 3 flights of stairs, so please bear that in mind if you are not comfortable with that. Also you will be asked to pay city tax on top of your booking price.