I would have to disagree with you. I took both AP and IB tests in Economics and Spanish, and to me the IB test was more about the amount of stuff you could write down in the time limit than about understanding. Since the test questions are virtually the same from year to year, it is easy to study the test rather than the subject, and I certainly didn't feel like preparing for the tests taught me anything in the anticipation-constraining sense. (I got a 7 on both, so I don't think this is entirely attributable to incompetence)

That said, the IB program is definitely more rigorous and meaningful than a typical public school experience, and saying it isn't up to the standards of LessWrong isn't really a criticism. I don't mean to be too harsh.