Very good links Colin!
I use Blizzaks on my truck and have run Michielin's X-ice II's. Two interesting.....well, not really that interesting observations.
Neither winter tire stops as well as I would have expected. I still get a lot of tire spin even being soft on the throttle. They also seem to skate on pure ice as much as the all-seasons that I've had (BFG All-Terrains). However, compared to Kumho KL71's that I used to run, I really had to be careful on slippery corners and the TSL's I used to have, they're were actually ok in the city but had no grip on the highway for some reason.
Point being, winter tires are much better than mud tires on ice and slippery stuff (obviously), but it seems people over exaggerate how wonderful they are stating the performance of their car equals that on dry pavement. If true, I want those tires!!!! But I haven't found them.
Editing to agree with the comment below about the winter tires being amazing on hard packed snow. That is very true!!