This review is of my WS70s bought this winter, but also my WS50s which I bought in 2007. Both sets of Blizzaks have been absolutely awesome and to be honest, I can't tell the difference between them. If you have never driven on proper winter tires then you will be astonished. When I bought my Mustang (305bhp/320lbft rear wheel drive) to use in upstate New York, everyone said I would need another vehicle for the winter. One lone friend told me that all I needed was good winter tires. He directed me to Tirerack. On my all-season (Ha) tires, the car was pretty much undriveable on ice and snow. With these studless ice and snow tires I have NEVER had any problem, and I'm a skier, so that means getting to the Mountains just after the storm. In six winters, I have seen at least ten accidents unfold in front of me in snowy or icy conditions and have never been concerned that I was going to become part of the accident. The car steers, accelerates, corners and brakes with great confidence. It would be a lie to say they have the ultimate grip of a summer tire, but they turn an unuseable car into a very good winter vehicle.
The only time these tires have caught me out is on wet pavement. On two occasions (in six years) they span up unexpectedly whilst accelerating pretty hard in second gear (The car is a Standard), but that was really my fault.
It is worth noting that in retrospect, I should have replaced them last year. The WS50s did about 30,000 miles and I expect the WS70s will be similar. The performance in ice was undiminished, but they started to struggle in snow because of insufficient tread-depth. I replaced them with about 3/16 of tread remaining. I'm sure this is less than Bridgestone recommend.