I don't agree. RWD with snow tires can do just fine but AWD will always do better in the same conditions. For me the slight (if any) performance edge that rwd has doesn't out weigh the safety and confidence of having awd on a snow covered road.
For the E90 crowd the Xi cars were actually quicker doing the quarter mile than the rwd counterparts because of the extra traction during take off. I was pissed because i had a rwd 6mt 335i thinking it had the advantage lol