Dear Peter,
If I were to shell out the dough for a Vibraplane, I might first of all put one under one or another of my turntables. Maybe the preamp/phono stage would come next. THEN the two monoblocks. But I am sure all of the gear could benefit to one degree or another. I do know that the amps sound much better when they are up on their Walker Audio tiptoes than when not. They sit on Sound Anchor stands, which themselves are up on Audio Physics tiptoes. On top of that there are butcher board slabs. Then the amps sit on very large Walker Audio tiptoes, as mentioned. I originally thought that was a good idea mostly to allow air circulation around them. However, I have found that they do improve the sound. Much more musical "air" when the amps are up in the air.