We picked this rental mostly because we could tell it was a real Roman apartment, not one of the bland, interchangeable spots one often sees. We weren't disappointed. It had charming decor, books on the shelves, and a sense that someone really lived there. Alberto and Francesco also provided a very thoughtful guide about things to do in Rome, with helpful tips (such as when to use buses rather than the metro), which we made good use of.
The location is very close to the crowds around Trevi, but the vicolo itself (where the apartment is) is mostly quiet (a bit of action at the nice restaurant below, which included morning produce deliveries, which were fun to watch from the window). It was super easy to get to everything we wanted to see.
The space is great for 2 - 3 people (my husband and 25-y--o son and I shared the apartment for a week and a half). Check-in and out were easy and smooth. Highly recommended.