Well, I now have a fibre kit feeding my EtherRegen, and even in the few hours I've had it up and running I can clearly state that the level of detail, texture and musicality have gone up a notch, without impacting the overall warm tone which I have grown to cherish.
After previously adding such things as top-notch ethernet and USB cabling (SOTM and FTA), Innuos Phoenix USB and the EtherRegen, it still amazes me how much more quality I can squeeze out of the DAC's input stream. Those out there who stick to the "1s and 0s" ideology are just wrong.
I consider the ER the best upgrade I've made to my system. And despite the fact it's galvanic and a moat (etc etc) I'm still struck that the quality of its input matters greatly. I'd already seen improvements after previously swapping the input Supra ethernet cable for a Wireworld platinum. Swapping the Wireworld for a decent fiber bridge just added more. Saying that however, the FMC is now fed by the same Wireworld. Go figure.
For completeness, I should add that I did try feeding ethernet into the ER's B-port and then feeding fiber from the ER's SFP to the FMC, and then to the streamer by the FMC's ethernet. Basically: router => ER => FMC => streamer. But this didn't work. The music was brittle and hard; the same reason I'd rejected a pure fiber ethernet stage months ago.
So, my ethernet feed is now:
Netgear Orbi satellite => Wireworld Starlight ethernet => ADOT FMC => Fiber => EtherRegen SFP A-port => EtherRegen B-port => SOtm DCBL-CAT7u => Innuos Zenith Mk3
Hopefully that is now me done. I have a credit card bill to clear. And I'll be avoiding reviews of the 2nd gen EtherRegen....
Thanks to all who contributed to this thread.