I've done it a couple of times, since 2013, and in both directions. Most recently, but well over a year ago, I sold my '14 Raptor for a '16 GMC Sierra 1500 Denali. Had the 6.2L, fully loaded (except ridiculous 22" wheels and power running boards....they later came out with the Denali "Ultimate"), very nice, sharp truck. I've had a lot of vehicles to compare by (49), so I do have a somewhat qualified perspective when I say I agree with you that the design, specifically inside the cockpit, is quite staid, quite boring. It's well put together, in my opinion, but certainly falls behind on what, say FCA is doing, or Ford. Yes, they added a bunch of outlets in the front for device, charging pad for center console, and nice LED interior lighting, but many valuable engineering opportunities missed for clever storage solutions (RAM does the better than anyone I've ever seen or owned).
Powertrain, the 6.2L specifically, in the GM trucks is superlative; absolutely superlative. Has amazing power, everywhere, and sounds fantastic. New 8 speed automatic is better at extracting engine's new muscle, and pulling better fuel economy out of it. However, as far as refinement, compared to ZF in FCA's products, falls far short. Far short. I reported on other threads my criticisms, in detail, on this transmission, whether in my Denali, or my Stingray, and will conclude again that GM's 8 speed transmission is NOT superlative. Follow Truck Trend's "2016 Truck of The Year" for detailed reports from them, as they experienced the same "banging", like being rear-ended by another vehicle, in their long term Denali test unit. Later reports indicate computer reflashes have remedied the problem; just pointing out there is an established history of some hiccups, teething problems....imagine that! Ford would never do that
.
Anyway, all in all, my '16 Denali was a very satisfying truck. Lots of muscle for towing. Good payload, since GM actually cares about that (some don't, namely RAM). To my eye, very handsome exterior styling. Good interior quality. Lots of technology overall, and yet lacking things I really enjoy in a modern vehicle, like push button start and passive, hands-free, keyless entry. Amazing overall performance, a pretty decent ride with the Magnetic Ride (although not as good as my '17 Rebel with the 4 corner air suspension and bigger, beefier sidewalls), and surprisingly good fuel economy--and I'm not easy on the go-pedal either
.
Of course, compared to a Raptor, the Denali seemed quite pedestrian, quite mainstream. Oh, I know, the word is boring. Loved the truck. But we're comparing against Raptors here!