i hauled cash or equivalents(t.c.'s) in excess of 10k to europe a number of times for a few years. also took more than 10k out of bank a lot of times, and deposited it back into banks.
was marked and searched upon exit of countries. still(20 years) get those extra patdowns. got tsa type patdowns. asked upon entry to usa "do you have excessive cash?" upon almost every entry. both my wife and i seem to have excessive luggage searches when leaving countries. a real nuisance, since after going through absolutely everything on the carryon, they have to find something.
nothing else has ever come of it. i have owned a number of businesses that deal in a lot of cash sales, and beg for audit, but that has never happened(i was audited in 1977 or so).
the biggest problem always getting the form and getting it to the correct office.