Our stay at Antonia & Michele's was wonderful.
They have a lovely apartment right in the heart of Rome - in Monti, which is Rome's grooviest neighbourhood on so many counts: everything's a walk from there... museums, churches, cool cafes, pizzerias and Rome's best-kept little secret: La Piadineria. Yum!
The Colosseum's a short walk away (2 mn), so is Termini - the main train station (10 mn), as well as San Pietro in Vincoli - the home of Michelangelo's statue of Moses (5 mn). A metro station (Metro Cavour at 2 mn), bakeries and groceries are a short walk away too.
The best thing about Monti is that it isn't over-run with tourists unlike areas like Trastevere (so far so good, but things are beginning to change). Here, you see more locals in the bars and piazzas. So in Monti, you do as the Romans do, literally :).

We highly recommend the restaurant Ai Tre Scalini on Via Panisperna - 5 min away.

Michele was very helpful and friendly. We were 3 of us and we had a good experience all through. The apartment is charming and the hosts have a great attitude.
We'd definitely stay there again.