I bought a 2019 AT4 6.2 in May 2019, had the Borla exhaust and cold air. That truck was a beast, but wasn’t great for towing or heavy loads. December 16 a woman ran a stop sign and I totaled the truck. Still dealing with her insurance company today! But I went ahead and bought a 2020 2500HD Denali! What a difference in towing for sure. I pulled a Polaris Ranger crew along with bags of duck decoys and lots of other equipment, I was constantly looking in the mirror because I never felt the trailer behind me. This is my first Duramax and I love it so far.