The apartment is as it is written, the location is very central. We reached everything on foot, you don't need any bus tickets. The Trevi Fountain is just a few steps away. We could wake up relatively late in the morning and look at the fountain when there were not that many tourists (the Trevi Fountain is the most crowded sightseeing spot in Rom to my experience).
At nights we could sleep really well, we didn't hear the tourists. However, there is an italian family store/bakery downstairs, who starts working really early and you wake up from their noise (dumping trash and delivery).