IsoTek and Audio Prism System Enhancers CD

I have owned Audio Prism's "System Enhancer" for about 10 years. I occasionally use it as directed, but have never been convinced it does (completely) what it claims. There are times I can hear some improvement, that is, the sound is less bright or edgy and seems more "relaxed"

AP provides a reasonable explanation as to how it works, but unlike a quality record cleaning system, I am still dubious of its effects. They now have a new version which is supposedly better.

IsoTeK offers a similar product with an added feature of cable burn-in, and also system sound enhancement, especially after a new component or cable is changed or added.

Would like to hear comments from members who have used one or both of these discs as to what sound improvement they have experienced. I prefer not to invest in the Mark II version of the AP "System Enhancer" if it either does not work or is only marginally better than the original. Thanks