This 2022 study by a professional audio engineer specifically regards the efficacy of spikes as a loudspeaker isolation device, however, the study includes tests, measurements, and graphs illustrating a number of findings that are broadly relevant to this discussion:
Magico Pods vs Townshend Seismic Platforms
I have a pair of Magico A5 loudspeakers fitted with Magico’s A-pods. Many here on Audiogon sing the praises of Townshend’s Seismic Platforms. Has anyone A/B compared the two products, particularly using A5 speakers?