I have used Vibrapods, Finite Element Cerapucs and Ceraballs under both a Rega Apollo and a Cambridge 840c.
Each of them do something slightly different to the overall sound. Vibrapods softened the edges a bit, I wouldn't call it smearing, but seemed to take a little of the upper edge off and relaxed the sound but imaging loses a small amount of specificity. The Cerapucs did nothing but thin the overall sound considerably in my system (both under SS and Tube amps and CD players). The Ceraballs had the best overall effect, improving sound stage depth and adding a sense of calm to the overall sound, but again had a SLIGHT thinning effect. I ended up using both CDP's on their standard feet. I do however use the Ceraballs under my Bryston 4B SST2 amplifier and it makes a really nice difference. They improve instrument and image placement (both across and front to back) snaps the bass region into awesome focus and adds really well formed heft, not that the 4B lacks heft, farm from it. They clear up the edge of base notes very nicely, leaving meat on the bones without any bloat, which my room can tend to encourage. They also smooth the upper highs and makes them very clear without sounding etched. A nice improvment in my system. I have to assume this is because of the two massive transformers operating in the 4B SST2 and the effectiveness of the Ceraballs to remove unwanted buzz and vibration.
Ceraballs are a wonderful tweak under the right component for the money involved. (my opinion and in my system).
