For a minute there thought you were referring to my ex-wife, lol!
I have about 45K miles on my 2015 and have as yet not experienced the dreaded Chevy Shake. It did however come down with the Terrible Torque Converter Shudder around 30K miles. Dealer performed TSB and so far no more shudder, fingers crossed.
about tires; I replaced OEM Goodyear Wranglers with Michelin LTX Defenders at about 35K miles. Have to say truck rides better now. But, I’ve never been happy with the ride of the truck. However, it is a 4X4 and is on rear leaf springs. So, have to take that into consideration. And, factor in that I’m just getting old and grouchy’er, so I’ve been told, lol. Being that I don’t have any major complaints other than the choppy ride when crossing tar strips in the road and such I’m going to wait till the 2020 comes out and see how it rides. I’m of the school of never buy the first year model of anything...