Teresa and Salvatore have been fantastic hosts, very reactive during our communications, friendly and flexible.
The property is about 20 min on foot from the central station (for those arriving by train, like myself, but also by bus or train from the airport), and really close to the Colosseum and the Forum. Essentially, it's really well located to discover Rome on foot, including the Vatican and any other interesting sites.
The flat itself is a reasonable size although be warned that there isn't a separate living room. The sofa in the wide reception/corridor is handy, but it is essentially a large bedroom (with TV), a decent-sized bathroom and a reasonable kitchen/dining room. You are likely to spend most of your time out exploring Rome so the place is more than good enough to go and crash after a few hours walking.
Considering the location and the prices in Rome, it is a very good affair.