Same here. I had a 2017 2.7L and it was the biggest piece of junk I have ever owned. Had 4 oil pans and they finally replaced the block. It stranded me shortly after block replacement and I got rid of that sucker as fast as I could.
We went to Yellowstone last week and we rented Chevy 1500's with the 3.0L Duramax. What a great engine. We were getting around 40.0 mpg cruising. Fueled up and had over 800 mi range. Makes me want one in a GMC.
Unfortunately, it's a take it or leave it situation. I'm ready for the direct to consumer buying model. No reason to buy a vehicle from a dealer. They only need to exist for warranty and service work.