Just a question, @antigrunge2. How did you determine that the system had "unprecedented impulse response" with your new feet. When some people use this term their thinking is that the system sounds "faster." What that usually means is that the bass is rolled off or a bass peak was removed (hopefully the latter). Bass can do a lot of mysterious things by moving the speakers or changing their elevation.
When a woofer is woofing at low frequencies Newton's reactive forces com into play and the enclosure wants to move in the opposite direction, the enclosure vibrates which you can feel if you put your hand on the speaker and play a 30 Hz test tone. Any vibrating on the enclosure's part is distortion. Either the speaker has to contain those forces by being very heavy and stiff. Or whatever it is attached to has to contend with tha energy. Now you have suspension feet. They are a mechanical filter with a resonance frequency dependent on the compliance of the suspension and the mass of the speaker. Below that resonance point the speaker is firmly attached to the floor. Above the resonance point it shakes and vibrates normally creating distortion. Consequently you want that frequency to be as high as is possible given the construction of your floor. It would be nice to get it above the audio band but highly unlikely you'll get it there. Assuming you have a very stiff floor the best thing to do is bolt your speakers to the floor. I have seen people putting granite on top of their speakers to increase their weight but that does not work. It just raises the resonance frequency a little. I built a set of subwoofers using 1 inch of Corian for the enclosure walls thinking that an insanely heavy enclosure would solve the problem. They weighed 200 lb without the drivers in, add another 25 lb for the drivers. It did not work. Back to the drawing board.
Anyway, if your system sounds good to you you are in business. Tinker On!