I just picked up a pair Nokian 160 mount and ground because of what Peter White has to say. but both seem to be good tires.
I have used two Nokian 294s front and back(Over kill for commuting) A Nashbar studded tire on the rear WHEN they were made by Kenda tires and still have a Nokian 106 that I purchased my first year of winter riding.
Some good reading for you.
http://www.peterwhitecycles.com/studdedtires.asp