My husband and I stayed here for a 2 night weekend trip. The location is great -- easy to get to from the airport (just a 10 min walk from Termini station). The apartment is very close to the Colosseum and Roman Forum (6-8 min walk). From there you can easily walk to see the rest of the central Rome sights. To get to the Vatican you need to ride the metro, but the apartment is close to a metro stop.
We met Valerio's father when we checked in and checked out, he is very nice! The apartment is clean and has anything you might want for a short or long-term stay.