I had bought used tires with good tread a year before ($200). It snowed in Washington two months later, and I couldn't even get up a small hill. I spent several months researching tires and had decided on Michelin Defenders a few years back, but couldn't afford the $860 price tag. I learned I was moving to Colorado and knew I needed to bite the bullet.
I could feel the change right away. Smoother, much more stable. When I got to Colorado and the snow hit I was a little worried about getting to work. Not a single issue. Most people say wider isn't better for snow, but I disagree. With these tires wider has been GREAT. Two days in, and I'm perfectly comfortable with controlled slides around corners for turning on purpose.
I'm just hoping the tread wear lasts as long as it's supposed to.