Really hard for me to interpolate, because I've only heard them in very different guitars, or with very different setups, but seems to me that the CS has more of a low mid grind going on, a sizzlier high end, its more open with rather a bit more treble and less bass, the PK is hotter, more mids and high mids, tighter, more solid low end and while still quite bright, less so than the CS.