Generally...the more agressive tires do better in deeper and softer snow, and the ones with more sipes and so forth do better on ice and hard packed snow.

Its mostly because the big knobby tread blocks can act like cleats for traction when they can sink into the surface a bit to bite...but on a harder surface, the big tread blocks can't sink in, and get no grip.

Something like a Blizzak on the other hand...with a gazzillion microscopic grip points, interacts with the surface more thoroughly, and can grip even ice.

Of course, in deep soft snow, those microscopic traction points are merely pushing snow flakes, and if you ever tried to pull your self by a snow flake, you know its tough going.

That's why no one tire does it all.

That's one reason I like the BFG AT ko too. Lots of sipes, lots of knobby tread elements.

Its not as good on ice as something like a Blizzack, or as good in deep snow as an MT, but is better on ice than the MT, and its better in the deep snow than the Blizzack. For me, that's a good compromise.

On the street, I've NEVER had a problem, I can romp through what ever blizzard we've had, and drive in circles around stuck SUV's, etc...the AT ko's have been awsome in snow.

Off road, I pretty much noticed the worst problems trying to go up hill on glazed hard packed snow...essentially an icy hill climb...and I noticed the Interco TrUXus (sic?) MT's, which are also well siped, did better going up it than the AT ko's.

So - choose your weapon.