I switched to Cooper ST Maxx’s after I completely wore out my KO2s at around 25K miles. The Coopers are “D” rated and I like them very much. They actually still have plenty of tread left after putting on another 20K miles, but they are just now starting to cup a little. My shocks are toast and I have a rebuilt set to swap out that are arriving next week. I do believe the cupping might be from the shocks.
The KO2 rubber compound is too soft for me, and they also have an annoying habit of picking up pebbles and releasing them when you get up to highway speeds. I’m definitely not going back to BFGs!!!