I don't know for sure about the SEI II, but I know Chris Sommovigo contends there is no directionality in his Studio series of cables and I'm guessing it's the same with his higher end cables, especially if there are no direction arrows on the ICs themselves (same with the Colibris). I just keep trying to use the Colibris in a consistent direction for my own piece of mind but have not heard any difference despite undoubtedly mixing them up from time to time as I swap to different ICs.
My experience is that even used cables/ICs need some time to settle in before sounding their best, so you might want to give them 100 hours or so before making any firm conclusions.
My experience is that even used cables/ICs need some time to settle in before sounding their best, so you might want to give them 100 hours or so before making any firm conclusions.