We really enjoyed staying here at Carmine's home. The location was safe and the security of the inn was definite! Although we didn't meet Carmine, he kept in great contact and had someone meet and explain things to us the first day.
The home is a bit a of walk to the colosseum and Vatican but it's not that bad. However after a long day of touring and activities, it can be pretty tiring. The metro system is great but only the bus runs near the home so keep that in mind. What we loved was how close we were to the main Trastevere area (great restaurants and shopping with a good atmosphere day and night).
The place will be all to yourself so that's also nice. Great place to stay if you want away from the touristy-ness :)