The location is excelent. Just a few minutes to Vatican, the castle and even all other attractions can be easily reached by walk. We did not use any transport except from airport and to the airport. The apartment is great for a couple. Cooking options are limited but we did not need them anyway.
WiFi is a little bit weak, so some mobiles might have problems, but PC´s did not have a problem at all and the speed was most of the time OK.
We were missing an iron board and a electric kettle. Otherwise we found everything, what we need.
I would not recommend the apartment to someone, who has a problem with stairs as they are small and steep, but they are not a problem for healthy people.