We stayed at this apartment for several days and it was very nice experience. The location is just perfect - 5 mins from Vatican and the neighborhood is very calm. The check-in and check-out also went all smooth and the host was helpful and nice, available for questions both via airbnb contact form and phone.
The small drawbacks: Internet in the flat didn't always function well and it would be great to have some salt/oil in the kitchen :)
Otherwise - great place to stay at!