I've read it those two books after LW. Assuming you have read the sequences: It wasn't a total waste, but from my memory I would recommend What Intelligence Tests Miss only if you have an interest specifically in psychology, IQ or the heuristics and biases field. I would not recommend it simply because you have a casual interest in rationality and philosophy ("LW-type stuff") or if you've read other books about heuristics and biases. The Robot's Rebellion is a little more speculative and therefore more interesting, Robot's Rebellion and What Intelligence Test Miss also have a significant overlap in covered material.