I can’t answer the question about cables, switches, regens and all that.
That not all cables are the same is confirmed by dCS when they say that you should use an unshielded cable conforming with the standard. This means that if you use a shielded cable you may be injecting noise into your system. Again: no bit loss, noise injection. The same goes with USB: the RJ45 input is clearly superior and that’s not a mystery. Maybe there are other ways in which noise can make it into our system via an ethernet cable? Who knows? There is galvanic isolation at one point, but noise is subtle and inventive, so never say never. I surely want to hear a HUGE difference before I pay big money for an Ethernet cable, that’s for sure.
Meanwhile, I found out that the Geistnote clock cables (less than 70$ each including taxes and transport from the USA to Italy) make my Rossini + clock sound much better than some other 75ohm cables in the same price bracket I was using. Much better is the key here. Not just a bit better, sometimes, with some kind of music. No. MUCH better. So yes, I believe in some cables, have an open mind, but I am not going to believe any marketing gibberish.
A.