I am very familiar with the Vibrasystems Sandwiched Blue Foam Pads, I was able to acquire these as a 300mm square that was a surplus material. I was also able to pass on as gifts these same pads to the local HiFi Group.
The Local Hifi Group are Gaia III users after my introducing them to the AT 616.
I also have used the same construction as the Vibrasystems Pad which is using a Sandwiched Cork. Each Types have been tried under as footers in direct contact with Sources, Amp's and Speakers and also as a Separator of Tiers in a Sub Plinth assembly.
My experience with these pads used as above is that as a alternate material in a structure they will change the sonic at the time of their addition, but are not able to offer a attraction that has been discovered from other designs for Footers that have been adopted.
My experiences of working with structures as interfaces for equipment and the loaning of materials and devices used for these purposes, has yielded very similar results to what has been realised when doing similar with a TT Platter Mat.
There is in my view no ubiquitous solution for a produced structure or use of a Platter Mat. When creating the experience, there are two factors to be considered. One being the capability of the device/materials in use to perform a particular function and then there is the unique preference for a sonic that is perceived as the most attractive to the end user.
The desirable sonic/presentation across a range of experienced users of audio equipment can be to the polar extremes. One seasoned user can prefer a lean transparent presentation, like myself, but where I stray is that I will welcome a little richness offered up for a certain genre of music, this makes my own preferences unique and I have worked to learn how to satisfy this within the used system. A SUT swap out, Platter Mat exchanges or a Cable or Valve exchange are easily carried out and more than enough to change the perception that a Lean or Rich sonic is presented.
Another seasoned user can pursue a Rich Warm Tone or even a Lush Overbearing Coloured Tone. There is certainly no correct or incorrect in my books, just end users who are happy with their creations.
As the OP's Thread Title suggests, A Journey has been undertaken to find a place where they are satisfied with what is used as a structure to get the best from their listening environment and to suit their preferences for how they perceive a sonic and presentation.
More importantly, as attractive as an Off the Shelve solution is, especially one that comes with a substantial purchase price, there is not any asurity, the sonic produced and the presentation is going to be satisfying to all who experience the device in use. For a selection of individuals it may be the very best experience to date, for a different selection of individuals the impression made may be quite different.
