On my last truck, a F150 I went through two sets of KO's and wasn't impressed. Within 40k miles has balancing issues and tread separation. When I bought my F250 three years ago I put on a set of Goodyear Wrangler Duratracs size 325/60/20. I currently have 45k on them and they still have another 15-20k worth of tread left and no issues so far. Think I'll stick with these when replacement time comes around.
A little update on my Duratracs. Currently at 63k and should easily get 70k out of them. I don't haul much but I am lead footed so I see my traction control light blink often. I imagine if I drove like a typical old man these things would easily get 80k or more out of them. Yeah a new set is gonna cost me 2 grand but with the miles I get out of them they are cheaper in the long run.