Demos don't count, but the only time I have ever seen pros in my life was at a black label demo in eindhoven 6-7 years ago. Melcher, Svitak, Rakestraw, Jason Adams, Alfaro and some ams that I've never heard of later.
I'm pretty sure I saw Wieger there too, I remember my friends yelling "hey look, there's wieger" and I was just "who ? never heard of him" and looked away.