Townshend seismic platform under my turntable was an incredible improvement. Just be sure to match the weight to the podium version selected. Doesn't remove footfalls however. To do that, I had to put my table on a wall mounted shelf. The improvement even without the shelf was so significant that I was willing to live with the footfalls and use the platform.
I also use Symposium products under my speakers, amp and phono stage and noticed nice improvements there as well. They clean up noise. The advantage to them is that they drain nose internal to a component and isolate it. That's why I like it for speakers. They make platforms with multicomponent levels and roller blocks that isolate by making the boxes float.
Remember though, proper isolation does not "add" anything, it removes the bad and lets the good come through. So, if you have a well isolated set up, rack or whatever, the improvement may be less.
I also use Symposium products under my speakers, amp and phono stage and noticed nice improvements there as well. They clean up noise. The advantage to them is that they drain nose internal to a component and isolate it. That's why I like it for speakers. They make platforms with multicomponent levels and roller blocks that isolate by making the boxes float.
Remember though, proper isolation does not "add" anything, it removes the bad and lets the good come through. So, if you have a well isolated set up, rack or whatever, the improvement may be less.