I really liked the MT/R's in the winter. On the packed snow (which is pretty much polished to form ice) they did pretty good, air em down a touch and its like a sunny summer day. Even on glare ice at a river crossing, they grabbed quite well, especially at lower rotational speeds.
I ran at 20 psi for a while with them, and while I wouldn't recommend highway speeds, they are quite nice on the side streets of Calgary that don't get cleared of snow.
They will flat spot in the cold, you will notice that right away, but once they warm up, the are a pretty darn good winter tire, in my opinion.
I'm jealous of other rubi owners who have managed to keep their original rims/tires.
Good luck in the snow!
Chris