I Got a set of KO2s as my first "real" set of All terains on my Tahoe (size 285/75R16, up about 2 inches from stock 265/70), and holy crap they blew away anything I'd run before. Now keep in mind, those previous tires were not even LT rated, and definitely not up to what I was wrongly expecting of them. I beat the hell out of the KO2s promptly, with a 8,000 mile trip, largely off road, through sand, mud, ice, and snow. They help up unbelievably well. Wish I'd taken some pictures of what I did to the sidewalls, but I had a sharp rock literally engulfed by the side of the tire when I got jammed up at one point, fully expecting it to blow as I got out, but it didn't leave a scratch. They have been wonderful in snow and sand. Mud, well about as good as you'd expect for a 6,000 lb rig with open differentials, but a hell of a lot better than before. I've run them everywhere from 18-45 PSI, and they have performed very consistently and predictably throughout the range.
Most importantly, they have seemed to hold up through their treadlife very well. My last set of tires were decent when new, but started getting significantly worse in wet and slippery conditions as they wore down. Tread life has seemed ok, though obviously not what I'm used to out of highway tires.