My understanding is AP test results are usually used to grant credit for college classes, and not as an admission requirement? I guess it could be a factor in admissions, too, but I recall mostly people doing it to get a bit of a head start towards graduation, rather than to get a better shot at admission. (People passing AP tests are likely to get in _somewhere_, even if not their first choice)

When I applied to college (recently, not that recently), AP test results were definitely used as part of admissions, in a similar fashion to SAT IIs.

ap testing is a lot shorter, clearly not as comprehensive, and graded very leniently in comparison

How do you know this? Many posters here commenting authoritatively about two educational systems...

What do you take issue with? The first two are clearly factual. AP tests are limited to a single subject and are 2-3 hours in length.

My comment on grading is also pretty objective, imo. Your AP score is 1-5. And the curve is crazy; when I took AP Physics C E&M I would have gotten a 5 whether I scored 60% or 100%. When reported, though, nobody will know what percentage of the points you scored. OTOH gaokao scores are reported in full.