I only had my car in the snow twice with the stock KDW. One time was with 5+ inches of packed snow with no problem but in a dinky storm with only 1 1/2 inch of snow/ice/slush I slid off the road around a bend (no hill) doing an entire 5 miles an hour (no lie). I had no control of the car (that's why I was going so slow.. When I checked the tires the entire tread gap was packed with ice turning the tire into a slick., i checked the tracks in the snow/ice/slush and there was almost no tred mark pattern in the snow. The tire still had a lot of rubber left.
Note to self: KDW and Snow not good. KDW and freezing slush very bad.
The potenza 950's that i currently have worked very good in 3+ inches of snow last Friday in the 225/50 tire size and tirerack only gave them a 6 in the snow. I passed at least 2 suv's that had spun out (one was a honda crv? if that counts).
But then like OfficerCarman said in philly were I live now there is not enough snow to worry, but i do worry about the A$$ in the 4,000+ lbs Navigator
I have 15+ years of winter driving in Pittsburgh / and other lake effect area's (north).