My speakers are kind of thin towers and spikes make me nervous that they could tip over. The speakers came with spikes that extend beyond the cabinets (KEF R500). I got Symposium Acoustics platforms that have multiple internal layers that both isolate the speaker from my hard wood floors and decrease (drain) the internal vibrations within the speaker cabinet. You see some more expensive speakers have this type of platform at the bottom of their speakers and usually some type of fat spike under them. The guy at Symposium was very helpful and not pushy at all. He makes some kind of discs that could go under the platforms, but said it might not be good to ride the height of the speaker from the original design, plus of course adding instability to the tall thin speakers.
They make several different platforms that he can recommend based on the budget and weight application. He cut them specially fro the dimensions of my speakers. Best of all the sound improvement was immediately noticeable with a more focused clearer sound. He under promised and over delivered.