I have two pairs of studded Nokian tires but the last few winters I get through on Continental TopContact Winter with no studs. Their benefit is that they work fine on pavement and thus in late winter or spring and let you plow fine into snowy and icy conditions. I still have to figure out fully how they work. For sure one issue is of the rubber compound that does become slippery at low temperatures. Second seems to be the fine tread that grabs small rock pieces that begin to work as studs. They are certainly not as good on ice as regular studded tires but typically they are good enough to get you through. They are just a different compromise than the studded tires but one which works for me during most winter. When it gets very rough, I put on W240.