After doing a lot of testing of router and switch and Ethernet isolators, I determined that in order to get the best SQ from Ethernet, one must use a good grounded LPS for the router/switch and it must be a good router/switch. My own switch is not as good as my router for SQ.
This is too much to ask of customers. The goal of Ethernet was to eliminate any SQ degradation by the ancillary equipment and software. Simply cannot be guaranteed with wired Ethernet.
Therefore, I devised a WIFI solution that has identical sound quality to my best wired Ethernet solution. This includes cables, a WIFI adapter powered from a Hynes LPS and an Ethernet isolator. It seems to be as reliable as wired Ethernet, assuming a strong WIFI signal.
If customers cannot get WIFI to their equipment rack, then there are other options, such as optical (Thanks to Ketcham)(still testing for SQ):
and AC-wiring Ethernet extenders - still being tested also.