Agreed that isolation on speakers can produce great results. I have been using spikes all these years and tried isolating the speakers earlier this year. It's a revelation for me.It seems against reason but isolating (not spiking)the loudspeakers works wonders, helps cure bass overhang, and stops room singing out of tune with kit, and cleans the sonic picture.
I use stillpoints under a couple of 50mm walnut platforms under Boenicke as swingbase don’t like carpets. Cerabase work well in place of spikes and Ebony footers I enjoyed, more for tonal qualities. I used to used my Lv obx rw sat on veneered chipboard plats to match bases, no spikes.(Kevin’s preference)
HRS Stillpoint is premium isolation. I would agree that different materials tend to produce different results. Not all changes are an improvement as some footers can make the sound worse. For this reason it is not a surprise that some people are unable to determine if the product that they use has brought an improvement or otherwise. The subtle difference may be a degradation instead of an improvement if it's used in the wrong place on the wrong component.