The location is perfect for anyone visiting Rome. One can walk to everything except perhaps the Villa Borghese and the Vatican...otherwise you are in the center of everything.
There is an elevator which is required otherwise you would be climbing what amounts to four flights of American stairs.
The apartment easily sleeps three or four (including one couple.) The kitchen is large by Italian standards and all three bathrooms have showers. One bedroom/bathroom is entirely separate and can be closed off. A second one with a queen sized bed is completely private with en suite bathroom. The last bedroom is really a comfortable loft space over the living room (with the oval portraits.) The bedrooms are reached by narrow open modern staircases pictured in the photos.
There are two adjacent living room spaces and while attractive and pleasant enough neither one is set up for comfort or as a welcome place to sit around and talk about the sightseeing that morning. They are basically one sofa in each room. (There are chairs and side tables about but combined with the lighting in the two living rooms you will probably sleep, have coffee in the morning, shower and then leave - which is fine on a vacation in Rome.)
There is indeed a washing machine but no dryer so keep that in mind if you are arriving in cold or damp weather.
Both Michele and his daughter Camilla were gracious when we met them and they arranged for a car service to both pick us up and take us back to Fiumicino at 45 Euros each way. Well worth it.
On the other hand, communication while in Rome with Camilla, who was in charge of us, was less than we had hoped. She was late arriving when we arrived and then it took two emails and finally a phone call to get a response about what to do with the keys and arranging the car.
The central location might ordinarily have come with lots of street noise but being in the small part of the Piazza and on what we know as the third floor, we found that the only disturbance (and it was considerable) was the upstairs neighbor and their child who ran constantly in the morning and the evening making a thunderous drumbeat on the ceiling above our beds. (Michele, who is an Italian movie star-like classical music conductor promised to have a word with the neighbors.)
In summary, if you are three people who want separate bedroom/bathrooms in the center of Rome, this is THE place for you if you don't mind the kid upstairs.