I have enjoyed my stay in Rome at Shiva's place.
The hosts are nice and helpful, they were flexible on checkin/checkout time.
The room / apartment was very nice and tidy with all necessary amenities including air conditioning system (which is really necessary during hot summer days in Rome). The only thing I wish was better: more natural light in the room (the room window faces internal courtyard which is not too bright but on the other hand there is no noise coming from the main street)
Location: very attractive - plenty of shops and good restaurants around, good public transport links to the other parts of the city (bus, metro), walkable distance to Vatican city (5-10 mins).
Note to people with disabilities: the apartment is located on the 4th floor of a high ceiling building and there is no elevator. I wouldn't recommend to people who have issues climbing the stairs.