I have to second the grip benefit, and snow is not required to experience it. All season tires get hard like a hockey puck, and pucks are NOT designed to grip cold surfaces. On clear dry pavement, you'll feel the difference.
When I bought my FFE, during the waiting for it to be built, the sales guy called to let me know a new incentive was available that provided winter's on rims with sensors. Selecting it would change a cash rebate by lowering it by about $250. Four sensors alone are almost that much, so I went with it.
They provided winter tires from Continental, I believe. One thing I noticed each year was that those winters dropped my full charge range by about 15-20 km, noticeable from the day they were put on (and raised the day the Micheline Energy all seasons were put back on).
A year ago, both sets of tires were due to be changed. I purchased a set of Motomaster winter tires (store brand from Canadian Tire) as we were purchasing a first set of winters with rims for my wife's Lightning at the same time. Canadian Tire has a 2-year no interest payment plan that takes the bite out of this sort of purchase.
Compared to the former winter tires, I have not noticed the range change I did with the original winters. I would definately recommend them if you're in Canada (or close enough to the border).
Last spring, I purchased another set of Micheline Energy all-seasons from Canadian Tire as I was happy with them.