I received some Vibrasystems rubber pads, and incorporating them into my Rega P8 turntable footers, they are definitely superior to the sponge puck / hockey puck stack: I stacked a standard hockey puck on a Vibrasystems pad under each footer, and the presentation is much more grounded, precise, and has significantly more distinct imaging in space. With the sponge puck / hockey puck stack, by comparison, the sound is more resonant and nebulous, with less distinct imaging. And for reference, the springs were inferior to the stacked pucks.
While the Vibrasystems rubber pads under the turntable footers made the most dramatic improvement, I also noticed an improvement (though not as dramatic) in presentation with the pads also placed under the tube phono stage.