2017 8 speed vs 6 speed

[2016LTCC]

I drove a 2017 silverado with the 5.3 8 speed for a couple of days and compared it to my 2017 with the 6 speed. And my conclusion is that the 8 speed seems faster shifting and probably better towing but it has a lot of quirks. I noticed some surging and hard downshifts. With that said I am happy I went with the tried and proven 6 speed but I do beleive the 8 speed has potential and once it has a few years, I wouldnt mind having one in a newer model. Ive also spent some time with rams 8 speed and always been impressed there but then again it has been around since like 2013.

[SteveCZ]

Oddly enough, the older mine gets the better it shifts.  Granted, I’ve changed all the fluids, and has new plugs and wires.  With the way the computer ties in the opening and closing of the TB during shifts, and whatever other trickery it does, seems like having a good running vehicle helps.....

[Z45]

My 2017 has 12,000 miles and the trans has been perfect, Sierra Denali Ultimate.  My brother has 25,000+ miles on his 2017 SLT CC 6.2L and says, no problems at all. Never been in the shop for anything but oil change.