We spent a week over the new year at Pieros flat.
The apartment is perfectly located in a quiet and safe area of the Trastevere with shops, restaurants and bars very close by.
The flat is well furnished and clean, and Piero was always very friendly and joignable to answer our questions.
We stayed there with 2 kids and could easely walk to all the places we wanted to visit in Roma.
The sole imperfection would be a lack of daylight in the apartment, but we stayed in december where days are particulary short. I'm sure it's better at other times of the year.
I definitively recomand the place.