The location of Simonetta's studio is fantastic and its surroundings are truly beautiful and quaint (a maze of little steps leading to colorful typical apartments of the trastevere area). I think this location is perfect for those who already know Rome and are more here to live in a more "roman" neighborhood and enjoy going out in the most lively area.
As for the apartment itself, it is simple but comfortable and convenient. The street is quiet but the walls between the apartments are thin so you can hear the neighbors pretty late sometimes. We didn't mind because we didn't go to bed before 2am but some might.
Overall, I would definitely recommend Simonetta's place for a young couple who enjoys being in a not touristic area, who likes going out at night and don't mind walking a little bit or taking public transportation to get to the center and get home to that peaceful roman oasis !