Antonella's place has a fantastic location. If you're going to the Vatican, this is the place to stay, it also has convenient access to the metro (less than 2 blocks away) and bus stops. Antonella was really helpful and gave us good suggestions on where to eat and get groceries, she even left me a map with some notes for places, bus stops, metro, etc.
There are supermarkets and several restaurants close by. The apartment is in a secure area and the access is pretty convenient if you're traveling with older people as there is an elevator available for use.
The only thing worth mentioning is related to the bathrooms, the shower area is small, so at some times you could feel really cramped when taking a shower. Also, there is no place to hang towels, which could be inconvenient if you're traveling with a big group of people.