Thank you for this thoughtful and educational response. I'm sorry I didn't see it earlier, as I'm used to other message boards where I receive an email if someone responds. In any case, I haven't made a decision yet, but everyone has given me food for thought. Thanks again for taking the time to explain it to me.
After reading what you wrote, I am wondering, do you have a favorite that I can just leave on? I admittedly do not change my tires according to the seasons, but now know not to trust the all season tires. Or do you completely recommend against picking a set and leaving them on? (I'm thinking storage for one, as well as $$$)
We live in Portland, Oregon, where we get, in an average year, maybe two or three days of snow; but we get something like 150 days a year with some rain. So I run tires year around that are excellent on dry roads and wet roads; but when it snows, the car stays in the garage. That also keeps me out of the gunsights of other drivers here who have little experience driving on snow and who foolishly think that "all season" tires will give them braking on snow equal to braking on dry pavement. When you are stopped in traffic, and another guy with no braking control is sliding towards you at 40 mph, it makes no difference what tires you have on your car: you're going to get hit.
If we lived in an area that regularly gets snow, and I felt that I would have to
drive on some snowy days, I would have a second set of wheels with Hankook Ice Bears mounted, and run those wheels from Thanksgiving through St. Patrick's Day.
Our practice of not driving at all on snowy days may or may not be an option where you live. We currently are running Continental ExtremeContact DW tires at the front positions -- I do not recommend that tire -- and Dunlop SP Sport MAXX TT tires at the rear, which I can recommend without reservation. I look forward to the time when the Contis are worn out, when I shall move the rear tires to the front and install a pair of the Dunlops (or their replacement "RT") on the rear.