I'm confused, is Old Yeller talking car tire reviews or bike tires?
Consumer Reports does testing on winter tires (for cars) every few years.
A Norwegian magazine also does annual ratings. I think this is the most recent one, with poor translation:
http://www.calgarycachers.net/red90/...ire%20Test.pdf (Note: I believe their top rated unstudded tire, the Continental Viking Contact 5 is also sold as the Continental ExtremeWinterContact in North America.)
Most of the online retailers also have user reviews.