Believe me I was hesitant when I bought it because of the price. I just had to try something better than what I was doing.
My body warmth went up noticeably. I've never had that experience from just wearing a cap. I can clearly go running in colder weather with that cap. Sweating became no factor at all where before it was noticeable.
It's not worth the money if are doing OK with what you have got right now.