We really liked our time at Sergios apartment. It is perfectly located to visit the traditionel part of rome by foot. You can also reach the vatican by foot, if you are ok with a 45 minute walk. It is a nice route. Furthermore Sergio is a very good host. If you need any recommondations for your stay, just ask Sergio. He waited for us to arrive, showed us the apartment and explained all relevanr details and recommended us some restaurants and other places.
Book this apartment and enjoy your time :)