Nordost Sort Fut supporting audio rack: does it work?

I see that the Nordost Sort Fut appears to be used by some as expensive isolation devices for speakers. I am set in that regard, having bought Ingress Engineering speaker footers. If you are reading this post and are using Sort Fut to support your audio rack, can you comment on the wisdom of this approach? If your rack is supported by Sort Fut or a similar product, do you also isolate individual components on your rack? Which brand of rack have you attached Sort Fut to, and how is this an improvement over the stock spiked feet, for instance? Thanks for sharing your experience with this application.