thanks for that review, amazing. good to know it makes that much of a difference. i can imagine how sensitive her back is to the rougher ride of the 22's. I take it that 20's make a big difference.I recently bought the 2014 QX80. After test driving both the base model with the 20" wheels and the high-end model with 22's, I asked my dealer to switch out the 22's for the 20's mainly because my wife, who has a chronic back problem, couldn't tolerate the ride with the 22's. The dealer changed the wheels to the 20's, we test drove the vehicle twice, and my wife loved it both times. I also noticed a big difference in "smoothness," which I expected because the metal-to-rubber ratio drops with the wheel size. Anyway, it rides like a dream now and we are very happy (but still in the honeymoon period).