amp platform suggestions...

Like Zephyr I have noticed that certain types of isolation devices work better on certain kinds of materials. Granite is very unforgiving of brass points, BDRs etc.

Granite is excellent if your goal is to isolate your component from any wall or floor born vibrations. The Herbies units you are considering (which I have) should be a very good match. So would Aurios.

Wood tolerates most devices and many people believe it to be warmer. I think there is something to be said about having a large block of wood as a reflective surface being more pleasing then having a large piece of stone.

Beyond the maple, take a look at some of the myrtle wood platforms being offered by edensound and others. Myrtle is extremely dense.

I have never been able to figure out why any kind of block or shelf would help with airborne vibrations. I think that this is where tube dampers and mass loading come into play. This may also be where devices like the Herbies and the Aurios which allow the unit to move freely make a contribution.

For very reasonably priced granite check out grizzly dot com and type in granite in the search box

I have also ordered thick cork sheets from McMasters and applied them to the base of the granite for massloading on top of speakers.

Two inch thick maple cutting boards totally bloated the sound of my system. Slow, confused, overly warm, muddy, you name it. Simply put, the maple cutting boards were terrible in my system.

WOW! It's amazing how the results have varied so much. Has anyone used a 1" thick polycarbonate as a platform?

Yes WOW - that's why the constant caveat YMMV

The Polycrystal, Symposium Ultra and Black Diamond Racing have all sounded good for me, as do the Sistrums. The Silent Running gear is supposed to be awesome. But you are in a different budgetary league.

Also FWIW - I have seen people argue that a cutting board does not sound good unless its made of end cuts or one piece. And here I thought that wood was wood...

Yes, I am currently using 1/2" Lexan shelves. Best solution I have found yet. And don't confuse Lexan with Plexiglas. Two different materials.

In time I may try two pieces of Lexan with a piece of acoustic felt in between. Not sure if that will be an improvement, but I want to try it. I have lots of Lexan so it's just a matter of getting around to it.