Actually, good studded tyres do amazingly well on ice. Both the lake / sea and the black kind. I've ridden in conditions where my biggest concern was staying upright after stepping off the bike, and getting on the bike again. My winter boots provided very little grip on the ice, compared to studded tyres. Once I got on the bike and moving, all was well.

I agree on the Winter Cycling forum, anyone interested should take a look in there. Quite a few threads about studded tyres, their pros & cons and whatnot.

--J