I definitely can recommend staying at Mario's place. He's very approachable and responds very quickly to aby questions you might have before booking a stay at his place. The stay itself is just as advertised :) Near to the strict city center, in the heart of the Trastevere district. It gives you a nice feel of being a part of the city :) The place is comfortable and equipped in everything you might need for such a stay. One of the big pluses is the terrace with a lovely overview over the district. It was a pleasure to be able to stay at Mario's :)