We totally lucked out with Angelo's place. Located in a side street running parallel to Corso Vittorio Emmanuelle II, location-wise, its centric location means you are fairly equidistant to the main tourist attractions (Vatican City, Navona, Pantheon, Trevi Fountain, Spanish steps, Colosseum and Roman Forum). If you enjoy walking, this is the place to stay.
There are also a number of nearby grocery shops, but you can also pop down the road to Campo de Fiori if you're after something fresh from the market. The interior of the flat is tastefully decorated, and the Airbnb pictures are an accurate representation. Spacious, clean, and comfortable.
While the centric location means you're within easy walking distance to the main tourist sites, it also means that you are within hearing distance of traffic, but this was negligible and wasn't a problem for us. Communication with Angelo and Francesco was great, and they were incredibly helpful.