That's no long true. There was at least one lawsuit (I think there might have been more) forcing the Army to reveal the details of the KABA after rumors that it was racist (surprise: it turned out it was).

Anyway, the DAPAR really is just an IQ test. I've taken IQ tests (real ones, that take all day and are administered by a psychologist and everything), and I took the DAPAR, and it's 100% an IQ test, albeit not a very thorough one. It's only broadly indicative, and most of the units that require a high DAPAR run their own IQ tests anyway.

The rest of the KABA is basically a socio-economic indicator. You get higher points for being middle class or above. Higher points for having married parents, for having parents with no debt, for finishing high school. It's basically a test of how "reliable" you are. And yes, you used to get higher scores for being Ashkenazi. Ashkenazim still get higher scores on average, but it's mostly because of correlation with other factors, and unofficial racism. Girls also used to get a lower score, just for being girls.

For those interested in the nitty-gritty, Professor Ze'ev Lerer, a professor at the Peres Center and Tel Aviv University, and former senior researcher at the IDF's Social Sciences Department wrote a book on the topic: הקוד האתני קב"א, מזרחים, אשכנזים

I haven't read it, so can't speak to its quality, but Professor Lerer certainly has the qualifications to discuss the topic.