Six stars on a five-star scale. Barbara was as amazing as her place. I was concerned that being on the first floor above a busy square, it would be noisy. Far from it. The dual-pane windows drowned out the noise excellently. The square is lively, with a daily open-air market. Excellent restaurants are all around. The location perfect to visit the other commonly visited spots, too. It's a 15- to 30-minute walk to almost everything you want to see -- the Vatican and Sistine Chapel, Piazza Spagna, Trevi Fountain, Colosseo, Roman Forum, Travtevere ...
The best part was Barbara. She greeted us warmly for check-in after we arrived on the train. She offered up printed recommendations for restaurants, bakeries, groceries and other shopping that were helpful and accurate. She gave us tips that helped us feel less like tourists and more like locals. The apartment was spacious, clean and bright.
I can't say enough good things about the experience.