We were pleasantly surprised at how close the apartment was to the colosseum - it's literally five minutes away. There is a metro a short walk in the opposite direction and lots of mini markets and cafes and restaurants within walking distance.
The apartment was a nice mixture of modern and rustic styles with a lovely patio to enjoy coffee in the morning.
We did not meet Matteo but he kindly arranged a taxi to meet us at the airport and his colleague met us at the apartment to help us settle in and provided a map of the area and a subway map too. He also recommended a good restaurant which we appreciated.
Also, I have to mention that in addition to the usual tourist sites, I was delighted to discover Profondo Rosso, a store very close to Vatican City dedicated to horror and giallo movies complete with a museum featuring props and features from the films of legendary Italian director Dario Argento. A must visit if that's your cup of tea :)