Location, location, location! Fabio's place was perfect! It's close to Termini station but if you're taking the Metro, Fabio suggested using Vittorio Emmanuele station, also on Line A, and a short walk from the apartment. Santa Maria Maggiore church was about 3 minutes walk. Lots of shops and restaurants nearby. Of course, the Trevi, Spanish Steps, Colosseum were all about a 20 minute walk. We did take Metro to the Vatican, so much easier than walking.
We will definitely recommend Fabio's place!