Now that I have an X1 at home, let me add to my original post about an EtherRegen connected in front of the Lumin X1. I use an EtherRegen from my network switch to take RJ45 into the eR and then fibre to the X1.
I feel that the eR takes a bit of the bite out of the streaming sonics of the X1. This is a good thing for me. This is compared to the fibre coming directly from my network switch. I found similar improvement with other fibre streamers.
The eR + X1 streaming into my Benchmark DAC3B into my RAAL VM-1a headphone amp is a bit too loud compared to my other fibre streamer, the Sonore OpticalRendu. I think I prefer the Sonore OpticalRendu a tiny bit more for fibre streaming. It seems a bit more refined compared to the full blast sonics from the eR. Though the sound is very close. I think this is a huge complement to the Sonore OpticalRendu since it cost so much less.
I am not using any super elaborate USB cable (maybe $100) or LPS ($300) with the opticalRendu.
The X1 used as both a streamer and DAC into a preamp or headphone amp is the best overall sound I have now.