I use a Super DIP between my Mac mini and PS Audio DLIII. Optical out of the mini, in to the DIP and use the BNC coaxial output from the DIP in to the dac. This provides an improvement over the optical out from the mini in to the DLIII. Not sure I'd call the improvement drastic. It is definite though, one of those " there's more there, there" type improvements.
I'm not sure the "super" designation means anything more than a different output configuration consisting of the BNC connector. But as my digital cable has the BNC on one end, it works for me.