Even my last dedicated set of Pirelli winter tires (Sottozero III) were complete garbage on snow and ice. Italians can't do winter tires. They can build Ferraris, Lamborghinis and Paganis, they can make Pizza and other delicious stuff. But they should stay far far away from winter tires.True on the variation in performance. I had 18" Conti DWS on my previous car that worked well. Check out this test winter test between the DWS and the Pirelli P Zero All Season Plus that I whined (yes, I was was pissy) about. The Pirelli performance is embarrassing.
My current Goodyear Ultragip Gen-1 are a night and day difference to the crappy Pirellis on snow.