I just use the Dex6 in my 2018 Silverado, I figure it's not something I'll change that often so why mess with something that is intended to not only work, but is the factory fluid?
I bought one gallon on Amazon for $17.50, delivered with free shipping (actually I bought two for $35). How can you beat that price and to your door delivery? I wish I had bought the AC Delco filter right off Amazon for $19...instead I paid $42 from the dealer (no gasket, just filter). It's amazing how quickly a good deal gets wiped out because you screw up on the next one.