First, the location cannot be beat. When Guido says it's 20 meters from the Pantheon, he's not kidding. You step out the door and the Pantheon a few steps away. It's also centrally located from all of the tourists sites in the city so made moving around easy.
The apartment itself is huge and nicely decorated. We were very comfortable and felt safe. Dozens of restaurants and bars are all within short walking distances and even groceries stores were convenient.
Guido also made things very easy with emails and arranged transportation for us from the airport.
I highly recommend the apartment.