anyone use a Symposium platform under a turntable?

Replaced the MDF shelf on my Target PS1 with a Svelt Shelf. Nice.

Depending on the turntable, I would think. Symposium makes a point that they work best when there can be good transfer of vibration from equipment down to the platform thus the aluminum pugs supplied with the platform.
I have VPI Classic which has rubber feet, in this case, Symposium really degraded the sound quite a bit (At the time I un fortunately did not try the aluminium pugs instead of the rubber feet). My friend has VPI HRx that also did not work well with Symposium. On the other hand, I heard Blue Note Piccolo which has metal feet with hard plastic cap that really benenfit from Symposium.
In case of VPI with stock rubber feet, I found Gingko works better.

I use Symposium Ultra under my Super Scoutmaster with rim-drive, which is great. All around better performance, deeper tighter bass, deeper soundstage, etc. I had a Gingko under my SSM before I went to rimdrive, which was very good, but the Gingko didn't work with rimdrive, as the table and arm moved laterally with the Gingko's tennis ball suspension system. I use Symposium shelves under all of my components, and rollerblocks under my CD transport. Need to use cones or point pod plates, not rubber feet for best performance.

I use the Ultra Platform under all my turntables. It is important to notice that you need to direct couple the plinth with the platform witch is acting as a subplinth. Never use rubber or sorbotane feet. Rollerblocks work well with VPI.

http://www.symposiumusa.com/VeysVPI.html

Use SYPOSIUM ULTRA Stelth Great bass wonderful imaging sounstage etc table is TW ACUSTIC AC1 With Black Night Power supply feet and VTA Armboard. Wonderful setup!!