We stayed a few days at Simone's BnB, and we had a great time! The place is spacious and clean, conveniently located in a quiet backstreet (away from the busy roads of Rome) yet everything is walking distance.
Simone is very nice -- the checkin and checkout went smoothly despite our plane being late. He is also accomodating of dietary restrictions for breakfast (vegan in our case).
Overall it is a very nice place to stay in Rome if you want to be at a walking distance from everything!