I agree - tread life is an issue with the BFG's, always has been. But some reviews I read are talking about 50k and up for the KO2's. So, we'll see as we're taking off for west coast trip from Florida in a month and a half. Will put enough miles on it then to give us an idea.
I like the ride and the grip, and the off-road capability to let that go a little bit. If I get 40k-50k miles, I'd be happy enough.
I read one guy that was complaining he got only a little over 20k on a set, but later in the post he said he always ran at the proper psi, 32 lbs on a 2500HD - YIKES, no wonder the tires wore out fast.