Re:
Nah, stock tyres. Geax Saguaros in 2.0. You need a decent amount of tread left, but on packed snow you're fine. Once you start hitting sheet ice, yeah, studs would be useful (and avoid the bruising), but I've learned my lesson on that - avoid sheet ice like the plague.
FWIW, if they behave anything like studded tyres on cars, studded tyres will be useless on anything other than ice and snow, and will be liable to throw you off on the road.
A bigger issue is ice buildup on your cleats if you need to get off and walk (like on that downhill section between the trees that finishes with a sheet of ice and which I should have got off and walked the first time). Not sure if spuds are better than crank brothers stuff in that respect, but I doubt it.