And on top of that, they give maintenance schedules (oil and fluid changes) that don't optimize longevity. Why would they? They don't want our vehicles to last forever, not needing replacement. My Sierra I have been changing my oil at 8k km (5k miles) and the 10 speed tranny's fluid at 50k km (~31k miles) to give it a fighting chance to live. From what I've been reading, most of the 10 speed valve body failures have been with the 6.6L Duramax crowd.
I'm just waiting for the powertrain warranty to run out before I replace mine with the latest updated one, which is a lot cheaper than the one being offered by Next Gen. However, I have an extended warranty for the valve body by GM but I'd have to get a failure/code before they would do it free.