While the science appears sound, real-life suggests differently. While with the Marine Corps I spent time in Norway on numerous occasions. Lots of Volvos, Saabs, Audis, etc. with AWD. They routinely blew us off the road in our Humvees. While I wouldn’t want to take one of these vehicles off-road (nothing beats a true military Humvee off-road), on packed snow they made us look like kids in soapbox derby vehicles.

Ultimately it comes down to experience and driving ability. I’ve seen plenty of "real 4WD vehicles" in the ditch during light snow; usually because the driver felt invincible.

Learn to drive the vehicle you have properly. Learn your vehicle’s limitations. Learn your limitations. And remember: you can’t drive as well as you think you can. (Just ask your friends and family; they’ve been trying to tell you that for years.)