I've heard quite a bit from other parents about the various magnet programs in the DC area and I'd agree that IB isn't the best fit for math/science types. Some of the local high schools have had very strong math/science AP programs for decades. I know that Wootton (Montgomery County, MD) regularly competed successfully against the top math/science magnets in the country in math and science competitions. I don't know if they still use the same structure, but all the AP sciences used to be second-level courses, preceded by the Honors course, and all were double-period. 80-85% of the kids typically had 4 or 5 on the AP tests. The IB programs had nothing comparable. The only calculus offered was BC.
le radical galoisien:
It really depends on the school.
ACSI in Singapore has implemented the IB program since 2004.
IB, despite being 'international', really assimilates to each host country's culture.
As I recall, the highest level math exams in IB cover linear algebra and ordered differential equations -- presumably that's what they would have to cover in Singapore in order to be eligible to replace the British A-levels.