I’m running the MBRP 5143 and like the sound a lot. It is noticeably louder than stock, but no where close to being obnoxious. It has a nice throaty sound, and there is zero drone at any speed/rpm. It has a nice quiet rumble at idle, but really wakes up when you get on it. The only thing I’ve noticed is you can hear a slight hissing at idle when standing directly behind the truck which is caused by the rear resonators. I thought about cutting those out, but I like the sound so much otherwise, I don’t think I want it any louder. You can definitely hear it in the cab with windows up, but can still carry on a conversation. I’ve had several people comment on how good it sounds riding in the cab. I bought mine from Summit Racing for $289.99. It’s a super easy cut and clamp application.