First, this is a comfortable place to stay. You have everything you need: large bed, good-sized (shared) bath, kitchen, balcony, quiet and authentic Roman neighborhood (with lots of great places to eat, shop, etc), near to transportation, near the Appia Antica, etc. If you want to get a true experience of living like a local, this is the place.
Second, besides all of the above, what really makes this place great is the host, Damiano. From the start, he was prompt with email replies, answering my questions. We booked him for our transportation to and from the airport, which was cheaper than a taxi and far more convenient than public transport. He really went the extra mile our entire visit to make us comfortable and feel like it was our home. He could not have been friendlier, nicer, warmer, more charming. I've found that the personality of a host is what can make or break your choice of accommodation, and Damiano definitely made it. Book this place - that is all!