We had a great stay at Gianluca's apartment. He was flexible with check in, and showed up right as we did - he gave us clear instructions and pointers about the area/public transportation. The apartment unit is located on the 6th floor and has an elevator, making it easy to get up and down the building.
Vatican City is a short walk away, and there's a bus stop very close to the apartment. The only issue was that there were no toiletries (shampoo/body soap) provided, which wasn't a problem for us since we had brought our own.