tvad4,
The Audiopoint disc is just a good compomise between protection and coupling. Does a little of both.
You hit it on the head about trying many different things because, as I mentioned earlier, sometimes what shouldn't work does, or what works for one component won't for another, and what sounds good to me may not sound good to you. I have Mapleshade Surefeet cones under everything (although being so massive I think they are not ideal for my smaller/lighter gear) and discovered, because I am an impulsive tweaker, that the sound of my amplifiers improved quite a bit when I turned the cones point up! That was a surprise (to me). Tried it with my Behringer Ultracurve and had the same results. Tried it with my preamp and DSP and I liked the sound better point down. Some suggest placing two cones point down and the other point up but I have not found that to produce the best sound. So some gear likes isolation, and some like to be mass coupled, and perhaps some a combination of both. And of course someone with the same identical gear might prefer a different sound and have the cones etc. arranged differently. It's kind of like seasoning to taste. The key is to try and find a sound that appeals the most to you even if it may deviate from neutrality. Takes some patience but there is lot to be gained. One thing is for sure, you don't know how much better an already good sounding amp, preamp, etc. can sound untill the stock feet are removed, thrown in the garbage, and replaced by quality cones, or whatever you find works best. Applies to speakers even more, of course, except you don't have to remove no steenking rubber feet!

And then of course some may read this and find it all a load of crap, and I almost envy the ones that do because I have driven myself nuts sometimes tweaking my system. Ultimately worth it though because I am very happy with the results.