Giulia's apartment was top-notch. Very clean, well decorated, and has all the amenities you need (plus some snacks). The washing machine is great to have if you have been traveling for a while and need to clean some clothes.
This is located very close near some little restaurants and grocery store. Close to the Vatican (about 5-10 minute walk). The Hop-On Hop-off buses are located near St Angelo's Castle (10-15 minute walk)
Giulia was very responsive and helpful in getting us to her apartment and even scheduling a taxi for us to get to the airport.
I highly recommend this place if you are going to stay in Rome.