Agree with John and Saltheart about the Korkers. It's like night and day. Even felt doesn't help as well (better than nothing but still not enough IMO). The only thing I've found that even comes close is the felt soles with studs in them. But they're such a pain to get attached you might as well stay with Korkers.
That's not to say Korkers will turn you into Spiderman. You can still be knocked down with them on (been there, done that)! But it's so much a safety feature.
Patrick, while I'm not a skateboarder I do believe most "professional" style skate boards have non-skid tape on them. Or thr pros add the tape. Either way I can see how a better rubber sole coating could help grip the tape. But haven't seen too many rocks with non-skid tape lately.
