Identical to the Marathon Winter, but with the studs only where you need them the most.
Are studs worth it? It depends. If you're regularly on ice, maybe. If you're on packed snow, or concrete, etc, they'll actually slow you down (and make a lot of noise), a good tire with a little bit of tread, at a slightly lower PSI than max, in our experience, works best.
If the bike lanes near you have anything other than packed snow, or bare asphalt, let your local city councillor know, shouldn't be like that.
If you're only getting one, put it on the front.