Simone's B&B is on a high floor in a residential building, in a very quiet location, very close to the metro (about 3 mins) or to bus stops, and just over 20 minutes' walk to San Giovanni. The room was large and comfortable, and we especially liked the bed - large, with tempur foam mattress and pillows. My wife has a bad back and very often complains about beds in hotels, but not this time! We also requested an additional bed for our son, and that was very comfortable too. The room was also really quiet. I am a very light sleeper and was never disturbed by any noise (however, I need to point out that during our stay the other room was unoccupied).
We never had any problems with the A/C, despite it being over 37 C / 99 F in Rome sometimes during our stay, or with the internet. The kitchen has a large microwave oven, a conventional oven, stove, and lots of cooking equipment, cups, cutlery, etc. We used the microwave oven to make our breakfast and it worked fine. By the way, Simone left vouchers for us to use at a nearby bar, but we didn't use them since we prefer to make our own breakfast.
Simone is also a very attentive host, always replying promptly to all our queries. Highly recommended!