"Audiophile Grade" Ethernet Switches - The new generation

[Snoopy8]

A direct cable connection between streamer and DAC (with high quality cable) is not better than any router/switch (EtherRegen or not)?...
It is less expensive, for sure.

It is better to improve the USB first, then later the switch because USB will deliver more benefits. 

I don't agree that USB is superior, at least not for everyone.

I've read comments from various manufacturers, some of whom say that USB is better and some of whom say that ethernet is better. ...

My experience suggests that 
generic Ethernet cable/switch -> streamer -> good USB cable -> DAC

produces better results than:
good Ethernet cable/switch -> streamer -> generic USB cable -> DAC

I believe Daniel was referring to the above common scenario.  DACs with Ethernet ports are less common and I defer to your knowledge of them.