I have owned two sets of these Pirelli's. The first was on a company Subaru Outback. I was so impressed I ordered a set for my 2014 JCW Coupe. I took delivery of my car just before Christmas 2013 so I had them put on immediately before picking up the car from the dealer. We get a lot of snow and a lot of snow types from 7-11 slushy to deep packed here in Colorado, not to mention ice.
The reason you get these is because you want some performance capabilities along with good snow traction. I drive through mountains, prairie and just took a trip to Vegas on dry warm road. I left them on because I could still hit snow in the UT and CO mountains. We have had a lot of snow this year up until about March so these tires have really had a good trial in lots of snow and in warm weather in Vegas and NM.
The snow traction is amazing. I have Michellin Xice on my company Malibu, Blizzaks on my Mini Clubman S and these Pirelli's on the JCW. I have driven all in sequence in several types of snow and ice. All are good tires but these Pirelli's are my favorite. They handle extremely well in the snow. I went in a snow covered parking lot doing donuts with and without traction control. It was really difficult to break traction. On the highway and on some icy areas they are fantastic. No snow tires make you impervious but I believe these are the best short of studded. The main reason I like them is because of the terrific dry and even warm weather traction. They are superb. I will not autocross in them but in a normal sedan or SUV I would consider running them all year. They do not seem to wear excessively and cold, warm, wet, snowy or icy they are terrific. There are no deficiencies. For a snow tire I would actually give them a 10 in dry but I think that is for summer tires. I think for price and all around performance in a climate like I have, -25 in winter and temps can change 50 degrees in one day and different altitudes...this is a fantastic tire. You won't go wrong with these.