So, I guess my Yokohamas and Johngenx's Blizzaks were happy accidents? 
I guess so. Both our WS-50's and Revo1's were excellent tires, with the Revo1's easily being the best ice non-studded tire I've had. They're not as good as some others in deep-ish snow, but on ice in my open-diff RWD Mercedes, shockingly good. The WS-50's are not quite as good on ice, but the AWD of the Scoob compensates for that and the better deep snow capability is great for the Forester as it is driven down quite a few unplowed roads in the mountains where the snow was deep enough that when we got out, we had to push the door through the snow.
The REAL KEY to winter highway driving is to put on good snow tires (any top brand) and keep your head scrwwed on right. The brain is the best collision preventer. Example? AWD is a fabulous winter driving aid, but can't defy the laws of physics. Many (most?) of the vehicles I see upside down beside the highway in the winter are AWD SUV's. See, momentum is momentum, no matter how many drive wheels you engage.
Example? Last May we headed to the Columbia Icefield for some climbing. Knowing we were going, I mounted the Blizzaks on the Scoob and sure enough, we needed 'em. It rained heavily and then the temp dropped fast, covering the road (no sanding or plowing) in a thick layer of ice which was then covered by fresh snow. It was some of the worst road conditions I have ever seen. Going over the Sunwapta pass, us and my companions (in a Legacy on studden Nokians) had to move slowly and the AWD as working like mad, but we managed to weave around the various cars sliding back down the highway. Geez, that would have been frightening, as the road is very twisty with some pretty serious drop-offs there. Near the top was an old VW Golf slowly making its way up. Guess who else was on snow tires? Two Scoobs and a Golf made it up, all on snows. We passed the Golf (AWD going uphill has some benefits) but then all three cars crept along at about 50 to the parking lot.
But, there were a few guys that didn't even make it to try the pass. Leaving the hostel, we were passed by a Pathfinderand an Escape that were FLYING along on the poor road. Yup, "I'm in my fur-by-fur so I can go fast." None of those twits even got to try the pass as they managed to go off long before. Too fast for conditions! We were in AWD Subarus (AWD system matches/beats anything) and on snow tires and we didn't get over 60km/h on the flat part, and these idiots went by doing 110 in a 90 zone.
Use your head, don't overdrive the conditions and use good snow tires. That's the secret. And don't worry about the car itself. I've often taken my RWD MB into the mountains (super poor city driving had me feel better about leaving the Scoob home for Wifey) and managed some horrific roads despite the so-called poor capability of my car. Good tires and engaged brain.
