We enjoyed the appartment and it felt like coming home each evening after spending a whole day in Rome. The airconditioning was very welcome with the heath and the terrace is a really an asset for this place. Marzia was a perfect host for pointing out nice addresses for us.
The location is a duality: Trastevere is very pleasant neighbourhood, with nice piazza's, wonderful restaurants, but since the appartement looks out on the piazza de S. Maria in Trastevere, you should be prepared to stay up really late :-) Sleeping before 1 or 2 a.m. is not possible because of the animation on the piazza.