We thoroughly recommend Luigi's apartment. Location perfect, just a 10 minute walk from the Vatican and away from the hustle and bustle. We were 4 people and had plenty of room, the size of the apartment is a major plus point. We felt very much at home and would definitely stay here again if we went to Rome. Luigi's restaurant recommendation was also great, we had a couple of lovely meals there and much better than tourist traps nearby.
Don't hesitate, book it and you won't be disappointed!