A couple of things to remember.........
1. The latest winter tires are the best.
2. SureGrip helps IF you have snow/winter tires.
3. If the tires spin, SureGrip will ALWAYS take the rear of the car to the low side of the road.
4. Audi Turbo Quattro is the best car in snow, esp. if you lock all 3 diffs.
5. Here is a case of the worst combo.
200 treadwear Z-rated summer tires, TracLock, 5 Speed V8 and me driving!