I have had the same experience with the same brand\model AT tires having vastly different noise levels with varying sizes. Case in point, the 19" Cooper Zeons on my wife's Rover are unbearably loud at all speeds - intolerable over 60+ mph; whereas, the 20" Cooper Zeons were only a bit noticeable on the freeway on my prior Rover Sport. There was no discernable difference in ride\noise\dry\wet grip with my Nokians on the road compared to the OE Wranglers; but, the Nokians have much better hydroplaning resistance and off tarmac traction. Interested to hear how the LTX AT2's perform on your Z71, as they are definitely on my list as potential replacements.