Great value, incredibly clean and well located.
The street is quiet at night but a short 2 min walk to bus stops on a main road which take you everywhere you can imagine wanting to go in Rome.
The room is cleaned every day and is in great condition - however it is below ground so don't expect a spectacular view - basically its a great bolt hole if you are not planning to spend much time in the room.
The bathroom was surprisingly nice - modern and clean - although not connected to the room it is private and only just across the hall.
Andrea and his sister Carla were fantastically helpful and accomodating - always making a plan for us if we had any requests.
Breakfast in the cafe down the road suited us fine - a couple of the waiters were pretty rude (but service in restaurants is not normally great in Rome anyway)
Location-wise its not right in the thick of things but close enough - I would recommend taking busses to the main attractions / to and from Termini station as its a bit too far to walk without exhausting yourself completely!!