The Q400 is very quiet compared to other turboprops. A nice machine all round.
Another operational benefit of a turboprop over a jet is it's ability to slow down alot faster on an approach than a jet, meaning you can hold a higher speed until much closer in. So much so that I was once asked to slow down as we were catching up a Ryanair 73 in front of us, and that was in a Shorts 3-60! Doesn't happen often though!