First, you are absolutely correct in fact. But that being said, if person A has no measurable symptoms, and person B does, then A's experience with a weighted

First, you are absolutely correct in fact. But that being said, if person A has no measurable symptoms, and person B does, then A's experience with a weighted blanket may not translate to B even if A experiences positive, measurable "improvement." So I agree that A's subjective endorsement is no good for B, but then again even if A had sustained objective improvement it still might be no good for B. At the end of the day, if B has real, measurable symptoms of poor sleep, the very best thing is a controlled test of people with the same symptoms of poor sleep. IMHO, of course. If my medical diplomas were laid end-to-end, they'd stretch from Albuquerque to Albuquerque.