Fantastic location and fantastic view of the entire Rome. Elisabetta's assistant was very friendly and shared plenty of information. We visited in December, it was perfectly warm inside, and I imagine it would be even more fun in summer — to make use of the private rooftop area. The kitchen was nice and well equipped, with welcoming touches.
A few minor drawbacks: the apartment itself (as well as the stairs, etc) was a bit more tired than it looked in the photos, but we quickly got used to it and felt at home. The bathrooms were rather tiny. I wouldn't recommend this property for people with disabilities, the stairs to the top floor are rather steep.
However, the view and the atmosphere helps to forget it all very quickly. We had wonderful time in Rome in this extraordinary apartment.