Originally Posted by The X Men
Those orders are only valid for stopping distance. If you are talking about accelaration in the snow, climbing a hill in the snow or getting unstuck when your rear wheel has no traction, then AWD w/all season tires > RWD w/snow tires. Another advantage of AWD is that if you can always add snow tires if one need more stopping power but if you want more traction in thw RWD with snow, you cannot add AWD.
The reason AWD feels more superior up the hill in a front engined BMW is because the weight of the engine gives traction to those wheels.
Porsche 911 RWDs have no problems going up hill in snow tires and do just as well as Porsche 911 AWD.