Humberto was a fabulous host! Met us at the metro when we arrived and walked us to his apartment (5 min from the Cipro metro). He showed us around the apartment and gave us a few good tips and a few trivia facts along the way.
The only thing to keep in mind would be that the apartment is located closer to the Vatican, but is necessary to take the metro if you want to visit the Colosseum/Trevi Fountain/etc.