I bought a set of Marathon Winter tires in 2009 and still use them for 2-3 months/year. Never had a flat and the studs, although not as sharp as they once were, still work well on ice. They're not great in loose snow, though. Also, be careful as studded tires on a smooth concrete floor (like a parking garage) is pretty slippery.

My other winter bike has Marathon XR tires (predecessor to the Mondial), which roll very well and have been very dependable for 10 years.

Spring through fall, I ride Marathon Supremes, which IMO are just perfect for commuting when temps are above freezing.