AWD is significantly different from 4WD - AWD delivers power only to the rear wheels until traction is lost, then it transfers power to the other wheels. 4WD delivers power to all wheels, regardless of whether or not they have traction. In the time period that AWD senses traction loss and transfers power, you can lose control.

I'm sure that's true for some AWD vehicles, but it is not true for either Subarus or Audis - both of which I have owned. Both tend to bias power to the front in slightly different ratios, but have some power going to all wheels by default.