Two main changes to the shoes: first, the studs you can see at the heel, and second, the anti-ice rubber thingy. The idea is that the studs will help him grip on ice, and the rubber thingy will help prevent those awful ice snowballs from building up in his hooves.
I know people go back and forth on whether to do studs &/or borium for the winter. I can see both sides, but ultimately, I trust our farrier. I also tend to feel that non-studded shoes are the most slippery thing a horse can possibly wear - far worse than barefoot, booted, or studded shoes. If Tristan (still, sigh) can't go barefoot in the front, then I'd rather he have the studs in.
Does the rubber thing work? Yeah, it helps. It's not 100%. Sometimes snow still gets packed in, but it seems to do so much less often, and it's easier to dig out when it does.