I enjoyed both of the books of his I've read, but you're not wrong. They're classic get rich quick schemes and get skinny fast schemes...not always based on the best science, or based on anything other than one data point (often his own personal experience). The value in them is more likely to be in maybe convincing someone to do something toward their goals, rather than providing a useful blueprint for what that something should be.

I followed his page on facebook years ago, and he trots out the "eating wheat causes you to have poop in your blood" article every year or so (there is no reason to believe "leaky gut syndrome" is a real thing, and Ferriss treats the guy who espouses that theory as though he is some kind of expert on health and nutrition). That's enough for me to take everything he says with a huge grain of salt.