the characteristics of a good preforming winter tire:
studs are dated. when installed, they are loud, and poor preforming in almost every aspect of winter. the studs can be spun out of the tire like gravel. the tire compound is always hard. studs are like chains, they have their place, on a vehicle isn't one of them.
the compound must be soft. leaving a visible dent with your fingernail is a good indicator. directional tread pattern is the best for braking while a symetrical pattern is quiet. open tread patern with a slight tapper to the lugs so they don't pack up with snow. sipes are a must for tire flexebility on ice. these are like suction cups. if your tire has more than 4 sipes per lug, they will wear out faster and warm, wet traction will decrease. the more sipes the better for slick black ice and a couple draw backs are that grip in loose packed snow is more limited, you hold onto more gravel and they wear faster. the compounds also tend to be softer. these are best suited for slick ice with little accumulation. under warmer chinook conditions winter tires in general slime up when warm and when wet, you will have a noticable decrease in overall preformance. hydroplaining can become an issue.
the make up of my ultragrips: they are soft when warm and in -25c, they remain fairly soft and plyable (not nearly as soft as the blizzak). they are directional and they whine the most at 50km/h. not as smooth as one would like. they have 2 sipes per lug. they don't slide much on black ice in emergency menuvering, though i wouldn't get to close to the the guy in front of you. braking on hard packed shiny snow is very impressive as is changing lanes through accumulation ruts with an icey base on the highway. these tires can handle everything including donuts in farmers fields, blasting through nice sized drifts and climbing in and out of ditches, but they lack the shear, black ice traction (not to say that it's not an impovement over the best allseasons). they seem to be happy with lots of snow. they are open lug with an agressive taper, snow doesn't stick at all, adding a solid footprint on any slick, snow covered suface.
acceleration off the line seems good but they are easilly over powered buy a heavy foot, half throttle is all they can hold with my van. i blame the directional patterns for this limitation.
low speed cornering and highspeed curves on highways are very predictable, but i still tend to hold my breath when i see black ice.
the short end with this tire, black ice.
total score 8/10. rough riding, and limited black ice traction. i would recomend as a good confident purchase that could take more warm running than the more devoted ice tires such as the blizzak.