Speakers do not generally behave microphonically but they sure do excite vibrations in everything else. Proper cabinet damping and use of isolation stands and/or rubber an be essential to reduced unwanted sympathetic vibrations. Same goes for anything in the room - heavy curtains may help with windows a heavy rug may help with a floor - tapestries may help with vibrating detached gyprock and on and on....Most speakers are poorly designed in this regard as are most generic listening rooms. These stands can make a big difference on speakers for this fact alone.
Electronics are usually challenged by ground loops, stray EM and power source noise that is not filtered well enough. Most of the noise in electronics comes from stray current through leaky components, heat and in general poor circuit design - so vibration pads or cones are unlikely to have any benefit although vibration damping may ultimately protect the longevity of electronics in extreme environments.I have spoken with manufactures of electronics (and owned their gear) who have gone to great lengths to mechanically ground internal components including transformers in addition to elaborate schemes of electrical isolation, etc. Proper mechanical and electrical grounding schemes have a profound impact on sonics. I agree that stray EM/RFI is a source of much sonic juju and is one reason why many philes have spent so much energy on various grounding boxes, etc. That is a whole other convo though.
shadorne, since you are the Ayatollah of rock & rolla, putting SS stands or any other products mentioned here under your subs and/or speakers would surprise you....