Generally speaking, soft items soften the sound, while hard items bring focus. I have used vibrapods, sorbothane pucks, brass cones, aurios bearings, and stillpoints.
The best item I have found is the stillpoint bearing. They give the benefit of spikes but maintain the speed and clairity that people tend to want.
The best item I have found is the stillpoint bearing. They give the benefit of spikes but maintain the speed and clairity that people tend to want.