We stayed for 3 nights at Gianluca's place. We had a wonderful time, the apartment was clean, spacious and was above our expectations. Walking distance from the Vatican, but if you do not mind to walk almost every site is reachable on foot. Just stroll through all the little streets and absorb Rome in all her beauty!
Gianluca gave us the good advise to park our car close by the Battistini metro station. Then take the metro to Ottaviano St. Pietro and walk for 10 min to the apartment. Parking close by in the parking garage is very expensive!