Along the lines you guys were going, I treat my components like I have previous rooms where a heavy mass is isolated from the room (double drywall hung on hat channel for instance).
I cannot say the sound is better, but I want to take every advantage so I use 3 inch maple slabs set on the Adonna rack rubber bumpers and then the component sets on isolation devices like Nordost Sort Kones. I'm theoretically isolating the component from the heavy mass of the slab. The slab, as wood, has a very low Fn as opposed to a slab of granite which has a higher Fn.
Perhaps a higher Fn is beneficial in some instances, but I would rather have a lower resonance as the slab.
Fn - natural frequency
Again, I'm not sure it "sounds" better, but knowing how electronics can be susceptible to vibrations (many years doing electronics packaging and vibration testing) I give it a go this way.
Happy listening!