I run Bridgestone W965 Blizzaks on my 2006 Chevy 2500HD, Diesel truck in the winter time. They stop real well on packed snow and ice and get great traction. Not tried them in a real deep snow, but I can imagine they would do about as good as any snow and ice tire out there.
After I discovered that all season tires where useless on my 2500HD in the winter, I bought the Blizzaks and mounted them on an extra set of wheels that I bought from a guy. I run Michelin tires in the summer and switch out around October or so each year.
I have found out that these heavy Diesel 4X4 trucks are so much heavier than the Tacoma's, Colorado's and 1/2 ton trucks, they don't go as good in the mud and snow in my opinion.
Tests have shown that all seasons are nothing more than glorified highway tires. For one thing, to get decent life out of them, they have to make them from the same hard rubber that highways use. Winter tires need soft rubber to have traction.
There are millions of cars out there in the snow that have less than perfect traction because of all seasons. The best thing is to do what you did...buy an extra set of wheels and have good quality snow tires on them. I have a set of studded snows for our van. It's a different world on snowy roads with those. While studs don't help in soft snow, you still do a lot of highway driving in the winter and they really pay off for that.
