Well, not all Saudis were bad. The one guy in my T-2 class would have probably passed if he was any other student. He was a little bit rough occasionally, but he was a pretty good guy and a decent SNFO. Always showed up to study, prepped for the briefs and did okay on the flights. And bonus, he didn't stink. He was definitely the exception to the rule though, on all counts.
A buddy of mine who instructed T-2's said the worst flights he ever had were with the Brazilians, they did whatever they wanted and often ignored the instructors. Scared the crap out of him a few times.