Best isolation cones

I've tried all of above, Nordost AC cones worked better under my amp than any. Didn't do much for pre. I have 4 of the BC 's coming and I'm not rich.

Truth be told , I have taken giant hard rubber bouncy balls from the toy store and cut them in half...place a little bean bag weight (from dive store) on top of the unit and WALLA! it works well. That's if you really don't want to spend money on these tweaks. Now, there are a bunch of expensive ball bearing oil cone feet you can get....but you might try the Brass footers from Mapleshade.com I use these big brass feet under my Manley Jumbo Shrimp and it works very well, also, They don't cost a ton either. I use 3 of them.

Your points are valid Mattmiller.
I can only say The 3 Nordosts replaced 3 large Mapleshade triple-points under my amp and are clearer and with more open soundstage.
Not night and day mind you, but enough for me to order 4 of the next up BC cones. Whether its worth the money is an individual decision, the Mapleshades are good.

I use the Big brass feet not the triple points. also, its for my tube preamp not amp, my amp is way to heavy to put feet under it. just for the info. I would love to play around with a set of those Nordost feet tho.