I opted for the SLT (custom ordered) over the Denali because for an extra ~$8K I couldn't justify the changes.
1. Bose and Navigation -- no desire for these with AA and Bose is just so-so.
2. Heated Steering Wheel -- yeah, I'm in Texas, pass.
3. Different Grill -- well, everyone in my neighborhood has a Denali of some sort, so the standard grill actually stands out.
4. 20" Wheels -- More sidewall on the 18's = less worrying about how close to a curb you are.
5. Forward Collision Alert / Lane Departure Warning -- yeah, I'd just turn them off.
6. Wireless charging pad -- I guess nice for my passengers, but with AA you must use USB and it charges anyway.
7. Ventilated seats -- this would have been nice to have.
8. Running boards -- not a fan and I'm leaning toward the AMP Research power boards for my truck.
9. Better Leather seats -- well that's to be seen, but I tend to take care of my leather surfaces frequently so I'm not too worried.
I think that covered all the differences vs. the 2017 SLT that I ordered, so for just the ventilated seats, I'll deal with it. Plus my truck stays in the garage when I'm home, too.
Edit: I forgot that Denali logo with the spray in bedliner, I guess I'll just have to live with the GMC logo with my bedliner