Recommended! We rented the appartment for two weeks and had a great time. We didn't see Monica, but met her friend Giuliano, who welcomed us and was very friendly and helpful. The appartment is spacious and cosy and has a lot of character. Only minor point is the matras in the separated bedroom, of which the springs can be felt. (There's also a bed/sofa in the living room, that is nice.)
The location is really nice: the direct neighnourhood is not so touristy, but all the bars and restaurants in Trastevere as well as the centre are within walking distance. And in case you don't like to walk too much, there's a tram right in front of the house that takes you straight into the center.