Roberto wasn't able to meet us personally when we arrived, but he sent very clear instructions about getting the keys and a personal note at the bakery a few doors from the apartment. All went smoothly, and the accommodation was exactly as described, comfortable and with everything we needed, and the location can't be beat: a short walk from the metro stop, and another short walk from the Vatican. This meant I was able to get in line very early in the morning for entry to St. Peter's one day, and the Vatican museum the next. Without that proximity I probably couldn't have gotten in to these extremely busy sites. Oh, and the fruit tart Roberto left for us on arrival was delicious!
Also, when I did meet him, at check out, he was the nicest guy ever. I will be back myself, and highly recommend this place!