Put Conti WinterContact SI on CRW alloy rims for the winter, stock sizes. Fit fine, no problems, look great. No snow or ice yet, but much better in the rain. They also seem quieter than the Ecopias. No difference I can feel in handling, but the grip is great (I'm running them at 43 psi vs. the recommended 41 psi). Maybe 10% penalty in range, but hard to quantify because of increased use of heater, lights, wipers etc.
Driven in the snow now, absolutely great grip. Thoroughly recommend.