Mr. Mitch2
Sorry you missed some of this tread, explaining that every amp-speaker has its optimum cable, by engineering calculation. The tweaks of a sound system shall be done other than on a copper wire between the amp and the speakers. No, no one cable for all. The cables are different by the equipment they serve and length required.
Not to say, that the claim is of having a speaker cable that would bring out 100% of a system, rather than have a wire you or others might suggest, that you think is good sounding, but would deliver only 20%-50% of that system's potential.
Please be kind to read the sharing on this thread, of people who made the change and were kind to share. None of the cable you are talking about would get this kind of improvement.