Whether they make a difference or not or if the difference is worth the asking price or not, the products come across as snake oil by any objective analysis regardless in most cases in that there is usually little information provided by the makers and people who pitch them often pitch them with no reservations and discount any dissenting views as best they can and still get away with it, usually by saying you gotta buy in first to know anything.
So if all that sounds good and appeals to someone, please have at it....
So if all that sounds good and appeals to someone, please have at it....