I don't run my Boxster in the Winter, but I have been running winter tires now since my 1st car in 1995. Blizzaks were the 1st winter's I ran back in 1995. They were good, but the technology is probably 20yrs old, and they are still charging a premium for it. I have run Toyo Observ tires and Michelin Alpins on my Jetta. We have 2 sets of winters for my wife's CRV. One is Cooper winters - with 2 seasons on them - we were given them when my sister in law traded in her vehicle, the other ones are Michelin Alpin tires with probably 5 seasons on them.
I am thinking that for winter tires, the price difference doesn't equate performance difference in everyday winter driving.
I have a 25mile commute, and in the mornings, the roads are often frozen and snowswept. The afternoon commute, the snow usually melts from the sun, and is not as slippery.
I might get new winters for my Jetta, as the Alpins on them are probably 5-6 seasons old. I may go for a cheap off-brand.
P