Valentina and Alessandro's place was great. They're super hosts and have made a wonderful oasis right in the middle of the city. The location is splendid, 5 minutes from the metro, walking distance to lots of stuff, and in a really interesting and relatively untouristy area.
Our room was light and airy and beautifully decorated. The shared kitchen arrangement worked well. Make sure you take Alessandro up on his offer of cooking a Roman meal... we did, and we really enjoyed it.