Is Spiking Necesarry?

@gdhal 
I completely agree. Whether on a joist floor or a concrete slab, I've always seen improvement with spikes. 

As for live music, most of the live music I've experienced is being broadcast to a crowd numbering into the 5 figures over megawatt line arrays rigs. I'm not familiar with any HiFi rigs that will modulate your voice or injure you if misused. I don't think it's possible to replicate the modern live concert experience in a residential setting. 

@gdhal   ??  What is the basis for your quite categorical claim in favor of spiking into the listening room floor?  I am still spiking my speakers but they are being spiked into Herbie's gliders!  Speaker vibrations are not going down the spikes into the concrete slab under the padded carpet and back up the spikes into the speakers!  The speaker vibration is being dispersed from the gliders into the carpet.  Those vibrations dissipate.  I had my speakers spiked without the gliders and with, with is it.  The sound is cleaner.  Perhaps my situation is aided by the fact that the deep bass is reproduced by my stereo subs.  BTW... they are also decoupled!  After decoupling them I did have to increase the subs bass level a bit as I was no longer hearing the smeared resonant bass coming back up the spikes.  YMMV vary, but it can't hurt to try it and listen for yourself.

@hifiman5

In answer to your question, and to be honest, I never heard/read of Herbie’s gliders. So I cannot say for certain that in my own experience spiking directly to the floor would be favorable to the gliders. At face value, the gliders do seem like a viable option/improvement over directly spiking to the floor. That said, I still believe and can say with personal experience that spikes through carpet onto wooden floor are preferable to rubberized feet and the majority of the speaker base being in contact directly with and only with the carpet.

I did not read on their website http://herbiesaudiolab.net/spkrfeet.htm whether or not "gliders" is indicative of the fact that one can freely and easily move the speaker. Question to you... in your experience can spiked speakers on gliders be easily moved? (i.e. the gliders easily move along carpet with the speaker spiked to them)

I'm calling BS on the sound going down the spikes and coming back up to be heard in the speaker. The speed of sound through air sea level air is 340 m/s. Sound traveling through a steel rod parallel to it's axis is about 5000 m/s. The speed of sound perpendicular to it's axis is about 3000 m/s. There's no way you're hearing that. 
I'm sure decoupling speakers from the floor sounds "cleaner". You're not hearing the busy details being randomly disperses by a resonating cabinet. 

I think this (spike) discussion is all over the place because we are mixing the applications. I always thought the spikes were provided for people who place their speakers on carpet floor. This way the speakers are, 1) more stable, and 2) they cut through the carpet and bond with the floor underneath. Hardwood floors; depending on sitting on a concrete slab or on hanging wood base, pose a completely different set of requirements. My most recent experiment of isolating the speakers from wood floor using damping blocks seems to give the least distorted bass. I could literally feel the very low octave vibrations in my listening chair with them sitting directly (on metal stands) on the floor. Those who actually like to "feel" their music under their seats and might prefer a solid coupling of the speakers to the floor...