Look into cross country sking, they are mostly running flats, TINY thin narrow skis, their wax glide is everything. Anyway as far as all mountain speed goes most racing is done up on edge anyway. And we havnt even got into weight..lol
WHY are their skis skinny and long then? That doesn't make more of a difference? Are you saying a pair of waxed powder skis would work better for cross country than nonwaxed cross country skis?