Based on my experience, I concur.
I've been running 4 Pirelli "Ice Radials" on my 850T during winters for
several years. I bought a set of Toyo Proxes 4 (high performance all-
season) last summer partly on the strength of ownership surveys rating
them equal to the Pirelli P-Zero Nero All Season. The Toyos performed
OK during several snowfalls we've had this winter. I never got stuck,
but they were clearly limited in their ability.
I recently put the Pirelli Ice Radials back on for a ski trip. What a
difference! I noticed it as soon as I drove out of our garage onto our
snowy driveway. The rubber compound on the Ice Radials provided a major
improvement in traction on packed snow and ice. As you would expect,
the tread pattern on the Ice Radials helped immensely in the deeper snow
I encountered in the mountains approaching the ski area, but that's a
no-brainer.
As an aside, I'm fairly impressed with the performance of the Toyo
Proxes 4 during summer and fall. Traction on dry and wet roads is very
good, they track very nicely on the highway, they're quiet, and they
balanced up very well. A good tire for the money. But when the tread
on the Ice Radials reaches the recommended minimum, I'll get another set
of 4 dedicated winter tires.
Java