Best Isolation Device for Speakers?

Not sure how a thread from 18 years ago got revived.  
The OP (hope he is still with us) mentioned sistrum stands, which actually couple, not decouple.  I had some as 20” speaker stands and now use them to get my subs off the floor, to great effect.  
I don’t however understand how decoupling speakers is beneficial, except to help isolate a turntable.  My speakers internally decouple the mid/tweeter, but I always thought the vibration from woofers should sink into the floors, rather than stay inside the cabinet.  Maybe the spring type action turns vibration into heat, and only transfers energy in one direction, so as not to allow drivers to push speaker back, etc. 

After years of using spikes etc I've become a fan of decoupling speakers.

Under my ATC SCM100 towers I've tried Herbies Giant Gliders, Isoacoustics Gaia and the Townshend Podiums. The Podiums produced the best results, but they're also the most expensive. For whatever reason I wasn't so impressed with the Gaia footers, but the Herbies produced good results and allowed very easy speaker movement making positioning a breeze. 

tobes  Thanking for responding in detail about your credible experience and knowledge with isolation devices AND the Isoacoustic Gaia footers.  I run the Gaia I under my ATC 50A actives with great affect, but respect that the Townshend may well be the ultimate.  And yes, they are expensive.  But then how much did we all pay for our ATCs?

@celtic66 I've read many reports of ATC owners getting positive results with the Gaia footers, so my experience is more of an outlier. The SCM100 towers required the expensive Gaia 1 model and maybe I was just expecting more given all the positive scuttlebutt. The other factor is that I sit fairly close - speakers in roughly a 2.5m triangle with the listening position - and the Gaia do raise the speakers significantly more than the Podiums or the Herbies footers. Perhaps that effected my impression? The Podiums were about 50% more expensive than the Gaia, bought direct from Townshend in the UK.

Worth mentioning again that fine adjustment of speaker position with both the Podiums and the Gaia is a bit of a pain - at least with my fairly heavy speakers. The Herbies made fine adjustment easy. I recommend the Herbies gliders - or some other furniture glider - to establish best speaker position first before installing either the Podiums or the Gaia. 

In my very humble opinion (I in no way claim to be right), I think most of you have ignored the facts that;

1) Speaker designs differ-the best place to start is to confer with the designer when possible. For example, John Devore does not recommend either coupling or decoupling under his O Series speakers. 

2) Many if not most loudspeakers are "voiced" for real world conditions;

3) Rooms and floors differ;

And most importantly of all;

4) There is ultimately no perfect solution to the vibratory nature of pistonic cones. Ricard Vandersteen may think so https://www.vandersteen.com/news/the-truth-about-pistonic-driver-cones but the truth is that his products don't ultimately sound per se better than many other competitive designs. The point being that you can tweak away forever but it won't solve the inherent deficiencies of pistonic drivers. You will hear differences that might strike you subjectively as being "better" in the short term but over substantial time you are unlikely to think that your system is suddenly the nadir of home music reproduction. Granted, there was this guy with 10K posts on this Board who claimed that Townsend products under a certain coffin-shaped cheaply constructed loudspeaker was "perfect sound" but we all know where that got him.