My company, 800score (a free site similar to Khan Academy), has helped millions of students prepare for the SAT, GMAT, GRE, and LSAT. My GMAT and GRE simulation software has been licensed to test prep companies and universities, worldwide.
I studied neurobiology at Cornell and English at Oxford. I scored a 99.98 percentile, cumulative, on the SAT, and 99th percentiles on the GMAT, GRE, and LSAT. The median SAT score of my 250+ in-person students is 1480. I offer a 270 point score increase/or over 1450 guarantee.
I've been to ETS and GMAC headquarters (where the SAT/GRE and GMAT are designed, respectively) and have consulted with their psychometricians. Kaplan wanted to hire me for their R&D department, and McGraw Hill offered me a publishing deal.
The SAT is used by admissions officers because it strongly correlates with undergraduate GPA. Ramping up college readiness will “ping” the SAT’s sophisticated psychometrics, resulting in a higher score with the added benefit of improved college performance. SAT prep should help you get into your ideal school and succeed once there.