Excellent location, especially for solo travelers who want to meet people and explore the busy areas of the city by walking. Most nights (it quiets down on Sundays) the party is right on your doorstep--I ended up at a disco with a group of new friends within hours of arriving in Italy! Apparently the city was busier than usual that weekend, though, probably due to the influx of university students for a new semester.
Sound was actually fine, although my room had a very pretty garden-facing terrace, not a street-facing window, so it might be different in different rooms. You could hear some muffled background piano-and-voices, but not enough to disrupt sleep, so I didn't need the ear plugs the hosts provided.