Hi rja
i don't use digital cables any longer so I can't comment on SX Digital. However I'm also really enjoying my SX balanced ICs vs SE. I believe it is indeed worth upgrading to the SX ICs, although my experience is limited to balanced, supposedly a completely new design by the late Roger Sheker. It is an easily audible enhancement (more body to the image) but still in the evolutionary rather than revolutionary camp. IMHO the SX speaker cable, although also offering improved images with more body, is a less convincing upgrade. That said, I have no regrets or buyers remorse, and am most satisfied with the improved sound of my system from the Audience upgrade. Good luck and listening to all! Thanks again to all respondents.