I went to Rome for some days with my husband and had a wonderful time at Mercuzio's place... although I never saw Mercuzio. When I arrived, a lovely Ann made the check up with us and took care of our breakfast every morning.
Ann doesn't speak any other language than italian so if you don't speak any latin language it can be hard to understand what she says. But she is really good at making you understand what she means and she is allways smiling ;)
The location is perfect to visit Rome because you can go everywhere by foot even if the B&B is not in the center.
The room and the bathroom is simple, but was really clean ! The price was really OK for a city where everything is really expensive -_-