Just wanted to add my experience to those who have found a significant benefit when adding Gaia's to speakers formerly spiked to a concrete slab. I have no explanation or technical expertise, but the improvement in image clarity was not small and (to me) well worth the cost.
Speaker vibration isolation
P.S. Audio has a video on YouTube, “RMAF 2018”, on Isoacoustic’s speaker vibration eliminator. The demonstration was impressive. Does anyone have experience with these, specifically the ones that replace the spikes as opposed to the stands? Thank you.