Interior is a personal issue. Some people love it, some people hate it. I personally have another comparable vehicle or two that I prefer the interior on, but I also know people who would trade for the k2 interior.
Reliability is another issue. Modern GM trucks (and SUV's, they are built on the same platform more or less) are not well built. Many people with experience with the brand will tell you to get a late model NBS (00-06/7) with low miles. The NNBS (2007-2013) vehicles had issues related to the engines and the interiors. The newest (k2xx) trucks are just poorly built. Things like trim break off, panels are poorly aligned, and lots of electronics fail, repeatedly. The quality control in general is poor. My father's yukon denali has a bolt sticking up through the carpet where you step to get into the third row, and another is about to come through. The antennas had water intrusion issues. the displays have issues. Intellilink/mylink isn't that great of a system imo. The 8 speed transmissions have major issues. The seats on the k2 trucks are much narrower than the older ones.
However manufactures sort out issues normally. Later NNBS vehicles were a significant improvement over early ones. Hopefully in a year or two the k2 vehicles are better built, because they are at heart a great vehicle. It's a blast to drive. The suspension is great, the engine has awesome power, it pulls a trailer like nothing's there. It's fast, stylish, gets great mileage and range, and it draws attention. It's got a million cupholders and pockets in the front. Passengers would rather take the k2 over the nbs or the pickup normally.
It depends on your situation. There's a trade off with everything. It will not be the cheapest or easiest vehicle you can own but keep in mind it's a massive hunk of metal with a giant engine, seating capacity, and towing capacity that is rivaled by few passenger vehicles. And despite that, it's relatively comfortable, manageable, and more than holds it's own in almost every category, against every vehicle. It's part deville, part corvette, part gmc truck, and more.