Federica's place is excellent. In the heart of Trastevere, the neighborhood we liked most: great bars, restaurants, bakeries, not overflown with tourists. Still, the Pantheon and the Vatican is about 20-25 minutes nice walk.
While being in a busy neighborhood, the place was quiet (except for the thin walls between the apartments so that we could hear the couple next door having sex at 4 am on a Saturday night :) ). Other than the busy Saturday night no earplugs were needed, even though I'm a very light sleeper.
There's enough space, the living room is comfortable and light, and there were a lot of nice touches, like a bottle of wine, milk and orange juice in the fridge, coffee capsules, etc.
We could definitely recommend staying at this place!