This morning I drove through a blizzard in Colorado on the stock KO2s with 20k miles. Everyone around me was doing 10mph because they thought they were going to die on their all-seasons. My worn KO2s didn't have any problem handling the snow and I would have been able to go much quicker if it wasn't for all the idiots around me who don't know how to drive in the snow.
That said, in Colorado, we deal with mostly packed snow and don't get ice storms. A softer tire with siping would do better on the ice, but the KO2 is hard to beat on the snow.