We enjoyed our stay in Mattia's mini-house. Although you are right in the city center, there is no street noise, as the appartment is at the end of a dead-end alley. The location near the Spanish steps is just perfect. The most important sites and things to see are all within a 30min walk. There are plenty of restaurants in the neighbourhood and even a small 24/7 supermarket.
After a long day of exploring the city, the jaccuzi is perfect for relaxing. And after that you have a big and comfortable bed for a good night sleep.