We loved Federica's place. Very clean and modern. The flat is about a 30 minute walk to the Coliseum, or a 20 minute walk to the metro which will get you most places.
We found it a small but reasonable space for a couple. My husband didnt really fit in the shower, but he is 6ft 6"(!) so its not a problem with the flat, but worth considering if you're bigger than average (I'm 5ft 8 inches and managed fine).
Overall we had a lovely time here, and the restaurants and bars nearby are reasonably priced. Would recommend.