I would definitely recommend this b&b for someone looking for a reasonably priced and comfortable place to stay. The sisters who run the place are very friendly and accommodating. The room and bathroom were extremely clean, as they are cleaned every day. The free breakfast (served 8-9:30) was excellent, as it offered several different options and was served outside in their garden terrace. The AC and internet worked wonderfully (both key selling points for me). It is within a 2-5 minute walk of the metro (very useful) and 10-15 from the Vatican walls.
Cons: The only small issues I had were with noise and bed comfort. The location is on a fairly busy street with a gas station and construction nearby. It was to be expected, but the walls are thin enough that it's worth mentioning. The bed seemed to have a spring issue as it poked a bit in the middle, and as it was a twin size (in my single room), there wasn't really room to move around it. However, it wasn't anything that would've caused me to move or complain.