This is also about the best way I'm aware of to take a direct shot at reducing digital "self noise" inside a component.
Bravo. Someone is taking the "discipline" forward through innovation. The whole concept of self-noise is integral to this discussion. It is akin to what Nordost demonstrated with jitter and cabling changes using software measurements. I know Starsound has provisions for formal testing in the works.
Total cost, about $500. How much better can a expensive stand improve on this?
There is only one way to find out! I have used Herbie's stuff in the past and it is a very good value. One thing to remember is that a lot of this comes down to system voicing. Herbie dots or Sorbethane or possibly Equarack can soften a front end that is prone to brightness. I have heard that....
...at the end of day most stands should be seen as a design element.
Au contraire. It is not decorative but is an engineered, holistic extension of your equipment. Again, that thought is a vestige of yesteryear. By way of analogy, look at how speaker manufacturers are pursuing mechanical grounding and isolation. Gone are the days of hollow, MDF boxes along with sideburns, tweed coats and crooked, yellow teeth...