I've been a firm believer in using 4 snows in the winter. Been doing so for 20+ years. RWD, FWD, 4WD, doesn't matter. I want the traction at both ends. Stopping and steering are at least as important IMHO as going. Its the least I can do to increase my family's safety as well as the others I share the roadway with.
My first Blizzak experience was about 11 years ago in a minivan also. Truly incredible. I know the naysayers will argue that new all-season tires are just as good. But it just ain't so. The compound of the Blizzak and other 'severe service tires' are made to stay flexible in cold temps. Hell, 70,000 mile all season tire compounds aren't flexible in 70 degree weather. How can they grip cold, slippery, irregular surfaces very well?
Almost all tire manufacturers have a Blizzak equivalent now (seen a TireRack ad lately?). If you have to drive in snow regularly, I recommend checking them out.
First winter I had the Blizzak's (on a FWD Windstar) I was going up the access road at Killington (Vermont) ski area. It was snowing and maybe 2-3 inches since plow had been by. I came up behind a Cherokee having trouble getting up the hill. I slowed to nearly a stop, then was able to pull out around an pass him, rather confidently. He had one rear wheel spinning and one front wheel spinning. The Cherokee tires could have been bald for all I know but none-the-less it was one of the few times I felt macho driving a minivan.
My $.02