I believe the X1 uses their new optical network which is supposedly quieter?
X1 owners must try the X1 optical ethernet input.
Many X1 owners in Hong Kong pair it with the Clones Audio switch or SOtM switch, both of which got SFP sockets for optical transievers.
Most transievers and the optical cables needed are much cheaper than a good audiophile ethernet cable.
Certainly, the sound can further be improved by using better transievers and optical cables.
I am sure Iscangus can give useful advice on these aspects for the X1 owners.