My 2001 with a 5.9 is way too loud. I don't care for the noise either. With 87,000 thousand on a 2001 it is going to be some time before I can order from a drive thru without shutting it off to order. Totally stock except for exhaust brake. And it's going to stay that way for a long time. Couple years ago this guy comes walking by, introduces himself as a retired Cummins engineer. He stopped by to chat as he recognized the noise from where he was parked. We had a long talk about various diesel things. One things he did talk about, was all the money it costs to have a pick up that sounds like a car.
Here's a cold start up form one with over million.
https://www.youtube.com/watch?v=VBIAY1l8H3w