Trainer Roller : polyurethane or metal? Some trainers come with a polyurethane roller not metal. I think that would be a lot better then the metal one. Has anyone used a polyurethane roller? And if so are they good or just the same as metal when it comes to wear and tear, and slippage ?
I haven't had a poly roller for long, only a season but I've never had any issues with slippage, though I always use a trainer tire on it.

Wear and tear I can't note any difference after a season of use other than some dirt and marks from my tire. Nothing deeper than surface dirt. Hope it helps!