Little nice apartment on the roof of a 5-floor building. Luckily, there was an elevator. The apartment itself was clean and spacious; with a comfortable double bed. View to St. Peter cathedral from the windows. At the back is a terrace with tables and chairs. There are 2 other apartments on the same terrace but I never have seen anyone else.
5-10 min walking to next metro station Ottaviano (line A), so you can reach most parts of center in few minutes. To Vatican museum entrance only 5 min and to St. Peter cathedral about 10-12 min.
All in all, a very recommendable accomodation.