Accurate in that its vague enough to allow for individual differences and different riding styles. I don't care for formulas and so forth except as starting points, like agreeing with the article in how it talks about KOPS, for instance, as sometimes working but sometimes not, depending on the ratio of tibia-to-femur in total leg length. I'd set a bike up at KOPS and then experiment a little with saddle fore and aft adjustments to see how they feel and so forth. Get stuff in the ballpark so you can ride comfortably and get some good miles in, and then fiddle with fine tuning over a much longer period.