When I was hunting for some AT tires for my 4Runner, I remember a fairly large thread of KO2 hate on the T4R.org forum. The consensus among the haters was that wet traction sucks in a potentially terrifying way about 20k miles in. It's a common complaint.I have nothing substantive to add other than this observation. Of all the tires discussed on this forum the KO2s seem be to the only tire that is either love/hate with no gray area. FWIW, a friend swears by these tires. As such, I took a hard look at the them. I bought a different tire.
Their tread pattern is great at throwing rocks and terrible at clearing thick mud. I had them on a CJ7 a while back. They're best in dry conditions. People in the SW US typically don't have much bad to say about them.
ATs are always going to give up some on-pavement manners for off-road performance. I think people mostly buy KO2s for the looks. Probably true of aggressive all-terrains in general, but the BFGs have been around so long, their look is iconic to many people at this point.
I just think there are far better options these days. If we didn't care about looks, most of us would be thrilled with a set of Defenders.