I was skeptical, but the level of performance raised way out of proportion to the price when I installed them in my amps. Bass got deeper and more tuneful, no question about it. Coating them with Walker's most excellent SST was also an improvement, especially in soundstage depth and imaging. Benefits were also there when installed in a PowerPlant, CDP/preamp, and speakers, although, as Brian found, not as dramatic as the amps (JC 1'S as well). I will probably install more of them inside the amplifiers when the upgrade high fades. It's a cheap fix.
