Usually I have been using studs every winter but this winter I decided to go studless seeing how good consumer reports rated the michelin x-ice. The pattern look aggressive and has alot of sipes but unfortunately for my needs it was not as good as what consumer reports raved. On new or packed snow it was sure very good and not excellent, on ice I found them very good and not excellent. It kept setting off the abs and traction control. Turning with mild acceleration the vehicle understeers with traction control enabled. Being severe winter condition tires (with the triangle emblem) I was not impressed with these new studless tires and will be going back to stud again.
Here is Kumho Izen KW19 unidirectional can be studded tire, which I found more predictable and very good on snow but good on ice. I guess the holes are there for you to add studs to them. Also there is not electronic gadgetry such as abs, traction control, etc. so everything is analog which I like.