Decoupling Speakers

Ok, back from Montana and found a pile of springs, cups, and Herbie's products in my mailbox. 

I decoupled my speakers yesterday, first by putting the springs and cups under the stands.  The rubber furniture leg cups I ordered worked perfectly with the springs as the inside diameter of the cups is just slightly larger than the springs and putting the cups up against the bottoms of the speaker stands created friction that did not allow the tops of the springs to slide against the stands.  I got it all set up and the springs seemed to be within their optimal range (around half-way compressed) but the end result was weird after going from a rock-hard coupling using spikes - where nothing was able to move at all to a springy support that almost allowed the speakers sway.  While springs are working well under my amps, which are much wider than tall, under the somewhat top-heavy speaker/stand set-up,  the springs allowed a more bouncy support which I perceived as potentially unstable if they were bumped into.  Therefore, although the springs I have under my amps are sized appropriately, I didn't really give the spring set-up a chance (at least for now) under my speakers and instead moved on to the Herbie's solution.

I replaced the springs with Herbie's Giant Fat Gliders under the four corners of the stands.  After letting them settle in on the carpet overnight, the support is much more stable than with the springs.  There is only a very small amount of movement caused by pushing on the speakers (compared to having them spiked), which may be in part caused by having the Giant Fat Gliders sitting on the carpeting.  Therefore, I am much more comfortable with the Herbie's Gliders than with springs from the standpoint of stability.  I need to give them some playing time before I report back on the sound decoupled vs. spiked.

For those of you supporting heavy speakers on springs, do you recommend stiffer or more moderate spring support?  In other words, how does the supported combined speaker/stand weight compare to the total available spring loading capacity....something moderate like 50% or something less (i.e., stiffer springs)?
In my recent trial, I believe the spring capacity that I used was too light, which allowed more side-to-side sway and less overall stability that I was not comfortable with.  That may be ok for stationary equipment such as amplifiers but I believe stiffer spring support is necessary for large/tall speakers.  Also, at what point are the springs too stiff where they are acting more as a rigid support and less as a decoupler?  What are your experiences?

Doesn't seem to be much interest in this topic but I will post my progress anyway and keep it short.  IMO, my system sounds better with the speakers decoupled from the floor instead of spiked to the concrete slab. Decoupling the speakers seems to have enhanced clarity and coherence, particularly in the midrange. Since I have two active subs, if I notice any loss of bass from decoupling the main speakers it can be adjusted for.

I tried Herbie's Giant Fat Dots, Herbies Giant Gliders, and springs.  I ordered the springs with too low a maximum load but was able to work around that by doubling up on the springs.  I have stiffer springs on order.  I put the Giant Fat Dots inside of rubber floor protectors as shown in the pictures.  The rubber floor protectors do better than the gliders at restricting movement .  

For now, I have ended up with a hybrid support system under my main speakers using Giant Fat dots in rubber cups under the rear of my speaker stands and springs under the front of the stands.  This seems to be a nice combination and it left the 8 giant gliders free to support my two subs.