Easiest way to learn is just get some A/S tires. You will know right away whether they work for your conditions/driving etc. That is what I did. I upgraded to summer tires on new rims and used the stock rims with the crappy A/S tires in the winter and the car handled fine for my conditions. If the A/S had not worked so well, I would definitely have gotten winter tires.
But for me A/S worked just fine. I know this might sound stupid, but I almost prefer a little less grip in the winter - its fun and it keeps me driving slower which I should be doing anyway.