As much as a love Silkypix, I have been recently forced to use Adobe Camera Raw (in CS4), because my new camera's RAW files aren't supported by SP yet.
(Adobe forces you to upgrade to CS4 to support the new versions of ACR.
I like the tools with ACR, but the preview image lacks sharpness. The sharpness controls barely do anything, and the interface just seems so clunky. The results are bland compared to my silkypix output.
Silkypix pro is due to be announced next month. I can't wait!
I also tried Capture One and found it to be very similar to Silkypix (it seemed to be more advanced). It doesn't support my new RAW files either.