Isolation stands: snakeoil?

I have not experimented with my TT isolation since it is a mass loaded TT which weighs about 120 lbs. For it, I borrowed Chris Brady's design which includes a sandbox at the top with legs filled with concrete which makes for a dead surface upon which to place the Teres 340.. Dance, jump, do whatever in front of the TT while its playing and there will be no effect. One person criticized the setup as being dead. Yet all I can say is that if my grin got any bigger it would bust my face open.
That said, I have played with CDP footings and when I had a lighter TT, different shelf materials. I can tell you that harder materials make for as brighter sound. Wood makes for a softer sound on the highs. This includes the rollerballs I use under my cdp. My wife was recently shocked at the sound difference of the different ball materials of the rollerblocks used under the CDP. I can increase or decrease the highs especially just by the material used in the rollerballs. Therefore I am a firm believe in footers for source equipment especially

Ooops - a typo - should have been....

It’s a bit like buying a hammer and then using it to hammer home SCREWS - it works, but it will never achieve that really strong joint.

Old Age :-)

"Soft materials?" You mean sorbothane? Why the circumlocution?
I worked with airborne sonars at one time and am sceptical about the transfer of acoustic energy to turntables through the air, since depending on frequencies and the size of the turntable or its components, the sound may bounce back or pass right by. Also the impedance mismatch between air and solid objects is considerable, so I can't see much energy getting in that way.
In any case why are there no measurements of this phenomenon to clarify what is going on?

The best turntable islolaters are the doors between the speaker room and the electronics room.  My ex-laundry room has all but the speakers. Of course, guests are not as impressed with the array of electronics, but that was never my goal. Another big benefit of this is the dryer's 10 guage wiring that now comes from a 30 amp 110 volt dedicated breaker.

I have my TT suspended through the ceiling by four cables into eye hook lag bolts threaded through a 1/2 inch glass shelf with nuts on the underside for leveling. Eliminates all vibration except for what travels through the atmosphere of the listening room. Cables are secured in the attic to conduit pipe that spans the roof trusses and is held in place with conduit brackets. I can't think of a better way to isolate a TT other than having it in another room far from the listening room.