I recently installed a set of their Auva 70 speaker isolators and was impressed with the result. I couldn't believe just putting them under my speakers could make such a difference.
I was using stock spikes on my JBL 4367's, carpet on concrete.
The Auva 70's improved pretty much every aspect of my sound, cymbals lingered longer in air with slower decay, sound stage had more depth and larger, I could get more sense of rhythm and melody in the music, bass was cleaner. I am very familiar with my system and an intent listener the improvement was not subtle to me, YMMV
The company is in England and allows an audition period. The 70's are the mid point. My friend bought 100's and is thrilled with his. We first heard of the company at Axpona.
Some years back I tried some Isotech stands and did not like the result and sent them back. The Auva sounded good in my friend's system but I wasn't there for the before/after. So I took them up on the trial and glad I did.