Turntable Platforms - Low mass? High mass? Why?

I guess I forgot to include spikes in the "mechanical diode" category. The Rega already has a "squishy" suspension right? So you're done!

The Rega philosophy is a light and rigid shelf or platform.Following this I had square piece of acrylic cut to size.Under the turntable you could have vibrapods under each foot.With a Rega P25 you have a 5 vibrapod at the back,a 2 at the next heaviest spot on the left and finally a normal vibrapod on the right where there is not too much weight.This sits on top of the acrylic shelf about 3/4 inch thick cut to size.You put some form of metal spiked feet under the shelf the same as those for speakers is o.k.The vibrapods were worked out after long testing and I can vouch it is effective on a Rega P2 although the original idea was worked out with a P25 and mentioned in the vinyl asylum and Stereophile.

That sounds like the way to go. How does it perform?

It cleans up the low-end quite noticeably and enhances detail.The vibrapods help the Rega feet drain away vibration as they are supposed to and the rigidity and decoupling effect of the shelf aids this also.

Bright Star Audio believes you should have a high mass (Big Rock 19) isolated with air Air Mass 19. Lots of mass isolated from enternal vibation. Problem is this stuff ain't cheap.