I bought these (with a new set of OZ Racing Ultraleggeras 18x8 square setup) to replace my last winter set: 17 inch Dunlop Wintersport 3Ds. Essentially, big shoes to fill, when it comes to snow/slush/ice performance. The Dunlops are that good in the nasty stuff.
These new guys so far perform just as well as the Wintersport 3Ds in the cold-and-wet/slush--which is saying something, with the Wintersports being outstanding--and better in the cold-and-dry (where the Wintersports let me down a bit). These Pirellis really feel like performance tires.
Here on Long Island we get at most a week of snow in the winter, and the rest of the time it's just cold and sometimes wet. And in these conditions, the Pirellis really do a great job.
Overall, the Pirellis are very good winter tires, but be warned, these guys are NOISY. They whine when unloaded (coasting), but quiet down when cornering, braking, or accelerating.