This is an exceptional place! It has two completely separate units (bedrooms) with their independent air condition / heating, and a newly refitted and very comfortable bathroom directly accessible from the room. In the middle, there's a fully equipped kitchen and a living room in one single space, also with dining table that will fit six people.
If this wasn't enough, the apartment is within a three minute walk from the St. Peter's Sq. and the entrance to the Vatican Museums. Metro is also a short walk away. Taxi stand is literally in front of the building, but the windows overlook a quiet street, so there's no excessive noise at any time.
Carla is also an exceptional host. She couldn't have been more accomodating and prompt with her replies. I have no doubt in my mind that when next time in Rome I'll look at this place first.