Had a similar debate with myself. Ultimately, it came down to what was in stock locally (as they had big discounts on the 24 models) and the drive of each model. I drove an LTZ, Denali and SLT. The LTZ had all the options including HUD - but honestly, the Chevy interior was not as nice as the GMC - the plastics seem to be a step down and trim pieces "look cheaper" maybe it is color or texture idk (High Country may be different - dealer didn't have one). After driving them back-to-back the GMC SLT and Denali were just more pleasant to be in than the LTZ. My GMC dealer had a short box Denali and a Standard Bed Max Tow SLT. The SLT had all the options of the Denali - minus the HUD (which I did want). You'll also note that the interior design is slightly different between SLT and Denali. But ultimately, I preferred the ride of the Standard Bed and Max Tow to the Denali with short bed and X31 and so with the added payload and tow rating I went with the SLT and decided the HUD wasn't that important to me. The interior design didnt matter to me as much as the drive comfort of the longer wheelbase; and the cost savings for the SLT was about $1500 which helped. I suggest actually going to look and drive; as I found the different trim and option packages actually felt different and looked different. You may actually prefer one over the other.