The gold standard that consistently gets great scores is TBR for chemistry, physics, and biology, TPR for P/S, and TPR and EK for CARS. If you sift through all of the threads with scores (not just the 509+ thread) you'll see people getting all sorts of crazy scores on both ends of the spectrum when they use Kaplan books and KA. Literally all of the people posting below 500 used KA, Kaplan's 7 book set, TPR sciences, and various other books and FLs. The lowest score I could find at SDN and Reddit for the gold standard was 506 and that was an anomaly. Nearly all scores using that set were between 510 and 528.
I got a 516 using that combination along with AAMC materials and ten FLs. Looking back on it now, I think the most valuable aspect were the answer explanations that taught me the material and test strategies. Don't skimp on passages!
