c) It does not fill up.
Not yet anyway. The race directors mentioned last year that if it keeps growing how it has been, they will have to put a cap on it soon. You can only get so many people down Blacksmith Fork! But it's a great race, highly recommended. You are virtually guaranteed cooler weather than along the Wasatch Front. Also a 50-50 chance of a good tailwind. Be wary of the sun obstructing your views of turn signs though.