I've had it installed for about a week and a half. There is a drone on the highway, but after hearing the drone with a muffler delete, it's not bad at all. Little more growl on cold start than stock, same at idle. Sounds a little louder than stock on acceleration in the cab. Haven't got to hear it outside the truck under acceleration or just revving. All in all, I'm happy with it. I do wish it was a little louder, but I could probably spend a year testing different mufflers. If I ever do change again it will be to a cat-back. That way I can go a little louder without increasing the drone.