I just got a 2016 Yukon with the 6sp trans. I have the same problem. There is a definite stutter/hesitation when I accelerate (not slight...very noticeable). I don't notice it during heavy acceleration, typically during a slow acceleration, most notably once I am in second gear (2nd gear, low RPM, engine under load). It's very noticeable when accelerating up a hill or trailering. First trip to the dealer was at about 400 miles. Tech said he didn't notice it - no work performed. Second trip was at 800 miles, I pushed to go for a ride with the tech. During that ride he noticed the issue (although the issue wasn't as bad of course since the tech was sitting in the car). He said he was going to do some research. End result was that they wanted to see if the transmission Active Sync (or whatever the transmission "learn" mode is called) would rectify the problem and that they would follow up at my first oil change. I took that as they have no idea what the issue is and unless GM puts out a service bulletin on it, they aren't going to try to chase down the cause. Meanwhile I have a hefty payment on a vehicle that isn't working properly. Any suggestions? Would a call to GM do any good?