Very good location (10-15 min walk to either city center or old Roman sites - Forum and Colosseum, 5 min to metro/main railway station), in a small lovely street. Supermarket right across the street, open till 10pm. Apartment is actually larger than it appears on the pictures. Cristina is a great host, very helpful.
Tip: use taxi from FCO airport, since it's cheaper than 4 train tickets.