American universities are clearly at the top of the heap in the world but the idea of meritocracy is sometimes nothing but a proclaimed ideal. For instance, 40% of the children of alumni get into Harvard compared with only 11% of ordinary applicants. More than 2,000 high school valedictorians are turned down by Harvard every year to give those on the inside track a clear and unfair advantage. In most Ivy schools, alumni children make up about 10-15% of the freshman class, as they are two to four times more likely to be admitted. A Department of Education report in 1990 concluded that the average Harvard legacy student is “significantly less qualified” than the average non-legacy student in every area except sports. At elite unis, there's a 25 times higher chance to run into a rich student as a poor one, too, since the fees are ridicuosly high, even though the median income family only pays about 30-40% of the sticker price due to student aid and other subsidies. Finally, there's the issue of racial preference but that's probably more of a political discussion. I certainly don't agree with it and think that real life factors such as parents income, etc. are more important. Why should a minority person with rich parents receive an unfair advantage over a caucasian guy with median income parents? Also, it's probably impossible for an American-born Chinese to get into an Ivy school without being superman. This is even sadder in face of, especially Harvard's role at the middle of the century when it opended up scholarships for merit to realise the creed of equality. There's much to applaud when it comes to American unis but the ideal of selection based on merit is on the retreat.
As for the APs, I thought the level of difficulty of my Calc BC and Physics C APs were about the level of what I had to pass at the German final high school exams. The French Lit AP was really tough though. But in any event, it's the universities where the US has the clear advantage over most of Europe (little federal intervention, competition between unis, funding from the industry, broad studies and generalization later, campus life, sports integrated, etc.). Anyway, the best thing is that you only need something like 70% correct on the science APs to get a 5.