Piera's place is wonderfully located in the heart of Campo di Fiori, walking distance from most of the sights you'll want to see in the city and many good restaurants. Piera was lovely, with refreshments on offer when she checked me in, as well as recommending me places to eat and see. The room is air-conditioned and has its own bathroom.
I will mention that if you're a light sleeper, just know that the room is facing onto a very busy street that often picks up well into the night, so be prepared for quite a bit of noise. That's the trade-off for centrality, I suppose!