Great place to stay. The best part is the location: not only very close to the Vatican, but also right near buses that go directly to the hottest sites (e.g., Pantheon, Roman Forum). We had a really easy time seeing all of the sites we wanted to see.
The hosts were very responsive and communicated very clearly. They were also helpful giving us directions from the train station to the apartment.
The room was great, too. It had all of the essentials, including A/C, reasonably comfortable bed (made more comfortable after a big dinner and a day of walking), good bathroom, etc. The second bed in our room was a pull-out sofa bed, which we ended up using and worked just fine.
Highly recommend staying here.