Which component(s) benifit the most from isolation?

The listener.. 

@bugredmachine Stack Audio Auva's under Wilsons, REL's, ARC preamp. Nordost Sort Cone under dac and amp. Iso acoustics under Aurender

Interesting assortment, can you describe the sonic differences between these brands/models?  I read great things about these isolation devices. Seems like a great opportunity to try all 3 under each component

Townshend seismic platform under my turntable. The platform sits on a wall shelf. The sound improvement from the platform alone was immediately noticeable, but created footfalls since my floor is suspended. I spoke with Max Townshend (RIP) who was a seismologist and explained why  it happened (earthquakes, waves, etc.). He said I could enjoy the improvement and deal with the footfalls, put the whole thing on a wall shelf, or live with inferior sound. Luckily my wife was OK with the shelf in the den. Just make sure the turntable weight is taken into consideration when ordering the podiums.

Symposium makes great isolation devices as well, (and they tend to be less expensive) but they have no effect on very light equipment (my TT is around 10lbs). I put their platforms under my speakers instead of the spike/disc combos that came with therm and they cleaned up the sound nicely (not as big as the turntable). I could have put their roller blocks under the platforms, but they said they wouldn't recommend changing the overall speaker height (the platforms were the same height as the cone/disc combos).

I was so pleased with the improvements that I then put Symopsium's roller blocks under my phono stage and integrated amp. Can't say I noticed a difference, and they have a money back guarantee, but I just kept them for peace of mind. I know they do reduce vibrations of the devices (I measured it), but that doesn't mean I can hear it. They claim it helps with power conditioners too, but I didn't go off the deep end to that degree. Same thing with cable risers. Remember @millercarbon? I think he sells them now.