ADD-Powr's concepts and assertions are rational. The Sym I/O audio benefits are not subtle. So you don't need to do blind A/B/A comparisons.
The products are worthy, cutting edge devices that offer more value to the quality of high end sound than any collection(s) of cabling ever can hope to achieve.
Do a little search here on Audiogon and you will find very few posts that show customer dis-satisfaction.
Open your mind. Ask the manufacturer questions. Contact a dealer and try any of the products for yourself. You have nothing to lose with a 30 day money back guarantee.
Maybe then you will be convinced intellectually and subjectively that the product
works.