As mentioned in other reviews, this apartment's location is just great!
Not only it's within walking distance from the main sightseeing places, it also allows you to experience a part of Rome that is not yet filled with crowds of tourists and still has this Italian charm.
With a small local market that is opened a couple of days a week, lots of places with good food and all those cute small shops, it's a part of the old town you definitely want to stay at.
The only disadvantage I could find about this apartment is that it can be a bit cold for those who get cold easily when it's not that hot outside. But the room has a heater, so it's fine. Some reviews say it can get loud outside, but we didn't notice this.
A special thanks goes to Zaira, Claudia's cousin who was our host and not only gave us a couple of suggestions about where to go (go to Gianicolo hill, by the way :), but was kind enough to let us check in earlier and check out later.
Definitely recommend this place to anyone visiting Rome - it will not be just a place to stay, but a part of your Rome experience