We spent 4 nights at Gianna's appartement, 2 adults and 2 teenagers. The (huge) place was large enough to accomodate us. It is tastefully decorated, with flashy color touches and nice furniture. It was also extremely clean. Since the windows are not on the street side, we couldn't hear any noise from the city. So, a VERY quiet place in general, except for when we could hear the people upstairs (which didn't happen often, and never at night). Perfect to relax after a busy day.
Gianna was there to welcome us and took her time to answer our questions. She was warm and smiling and really nice. She had a folder with lots of information about the area, the city, transportation, etc. She also recommended a local pizzeria that we checked and enjoyed very much (no tourists there, only locals!).
There's a tiny minimarket just next door - very practical to grab some food on your way home. A larger supermarket is 5mn away.
The subway station was about 10mn away, but there's a bus terminal just around the corner - very practical. Plus, walking to Vatican Museum took about 15/20 mn, St Peter's and Castel Sant'Angela are 10 mn further. So, Gianna's place is a good place if you want to walk to the city's attractions, rather than pay for public transportation.
Also, following Gianna's suggestion, we used a chauffeur service from and to the airport, and at 75 euros round trip, it was definitely a good deal for the four of us: 35mn from door to door, and the pleasure of being driven around. It obviously costs a bit more than train/bus, but not that much considering what you get for the price. We strongly recommend using this service in Rome, if you're a small group.
Altogether, a great appartment with a unique decoration, at a very good price, and well situated.