What Are Your Experiences with Decoupling Products and Your Recommendations?

I've heard IsoAcoustics to Stillpoints are the way to go. But I've also heard HerbieAudio is a great (inexpensive) alternative and not over-engineered. What has been your experience and what in your opinion is the cost/benefit threshold?
Decoupling is a misnomer, and a misconception that leads people to make mistakes. Every audio component generates its own vibrations. This happens internally and independent of the environment. Aside from really large amplitude low frequency vibrations like from people walking around these internally generated vibrations are in fact the major source to be controlled. So even if the component were somehow floating midair we would still have the problem of vibration control.

Once correctly viewed this way suddenly we are free to see the problem for what it is. The goal is to support the component in such a way that it is rigidly held in place. We know we don’t want it floating on something soft, because when we try this it sucks all the life and dynamics out of the music. But we also know we don’t want it so stiff that it resonates and feeds vibrations back into the component. Glass for example.

The ideal material would be one that is hard, but not too hard, and stiff, but also highly damped. Every material has some sort of resonance. Ideally this would be a material that drives vibrational energy into a resonance frequency far above the acoustic range.

Composite materials have all these properties, which is why for some 30 years now the industry leader in vibration control is BDR Cones. At $20 each they're one of the greatest values in audio.
I keep telling millercarbon to go to the library but he thinks he knows it all already. The mass-on-spring isolation system prevents low frequency vibration from being transmitted to the component from the floor AND damps vibrations that are either induced on the top plate of the iso device or produced there by acoustic (mechanical) waves. So, the iso device works BOTH WAYS - 🔝and ⬇️ Problem solved! 🤗 It’s not rocket science, folks.