Looks like I'm a bit late to the party but since the party appears to still being going strong, I'll add my input.
Just purchased a 2020 Silverado LT Z-71 3.0 Duramax and really enjoying the truck so far. The COVID-19 slow down has me working from home much more so I still haven't put more than 800 miles on the truck and averaging 22mpg. Mileage should be a bit better and may get better with time but I'm sure the Durtracks are hindering the mpgs.
Like many of you, I traded in a '16 GMC Canyon with a 5.5 BDS/Fox lift, 33" tires, and the 2.8 Duramax. Great to look at and great fuel economy (23mpg avg) but not so much fun on the road. Felt like I was about it roll it going around most corners at anything over 50mph.
The new Silverado 3.0 Duramax and 10-spd transmission is so much better than I anticipated. I've owned a stock Cummins 5.9, fully tuned Cummins 5.9 with built transmission, 3.0L Audi with 8-spd transmission (awesome), and 6.0L gas Silverado. This combination is the best by far and even eclipses the Audi for both torque and HP. If you are reading these threads and on the fence about purchasing one, don't be. Just jump to this side. As you can see from our reviews the water is fine. And if something does go sideways, the 5yr/100,00mile warranty is there to "help" us.
There are many things that I dislike about the truck but none of which have to do with the engine or transmission. Will just take what I have and slowly make it what I want with a build-thread to follow in the near future.