Old thread, I wonder whether the OP bought a truck already.
I've had a 2016 Tahoe LT from new, it has 95K on it now. It's been fine. Here's what I have to say:
The only non-wear maintenance issue I've had to address was a leaky front differential at about 70-75K. About $900. Otherwise it's been fluid and filter changes and that's about it.
I'm still on my original brakes, believe it or not, though I need to replace them soon. I live in Colorado and drive in the mountains a lot; I am obsessive about engine braking.
The 2016s do have CarPlay. It works fine mostly but there were a few gremlins in the system. Sometimes it doesn't see the phone, other times the controls simply don't do anything. Sometimes they work but with a weird latency, like you push the button to advance the track and 45 seconds later it does.
The 6 speed transmission works well but is not super elegant. The shifts are not fast by modern standards and you can easily fool it into thinking it needs to downshift via certain throttle patterns (which doesn't always happen on purpose). My other car is a 2016 Porsche 911 with the otherworldly PDK, not a fair comparison but does exhibit what is possible. The GM 6 speed was a very old and reliable design, it's not a miracle of engineering but won't often break and will be reasonable to fix if it does.
The halogen headlights are abysmally bad; not sure if the GMC ones were any better than Chevy in 2016, as that is a clear difference in design between the two. I've tried every possible upgrade; the plug-in LED bulbs seem to fail quickly. An improved quality aftermarket halogen bulb has been the best choice, but still light years behind good headlight technology, even in 2016 and especially now.
I feel like mine has begun to ride less well than it once did; probably time to look at replacing the shocks. Our roads in Colorado are awful because of freeze-thaw patterns, so I maybe should not be surprised. Although I've had other vehicles this old here that did not exhibit the same degree of degradation.
All in all, it's been a good truck, very well suited for what I bought it to do but it does suddenly feel outdated to me. I feel myself wanting to move away from it, but maybe only because I've had it seven years and it's time for a change.
