I just watched Richland Park HT's - this is a 3 star rated course where Phillip Dutton, Karen O'Connor, Darren Chaicchai *sp* and many other big named Olympic Riders compete. Every year they host a HUGE comp ranging from Novice *fences are MAXED out* to 3 star.
I saw TONS using their skull caps at Novice and Training. Minimized from Prelim and then above that they were all in top hats and shade bellies.
But on the other hand, there were just as many doing CC in their IRH's or Charles Owen velvet helmets as well. I even saw a few Tipperary Sportages.