I have been using Sonore Optical Rendu for close to a decade now. I had the Lumin X1 DAC/streamer which was $15k. The DAC is OK and the streamer in it is great. You can buy that streamer standalone now as the Lumin U2x for $10k.
I also have the PlayBack Designs STREAM-IF for $3k and that was also great but I only used SPDIF since I did not own a PBD DAC which has fibre optic connection (via PLINK) from the STREAM-IF to a PBD DAC.
I also had the ROON-ONLY OpticalRendu. I compared all 3 streamers side-by-side and found they were ALL great,but sounded different. I ended up selling the Lumin X1 and the STREAM-IF and bought 2 more Sonore OpticalRendu's.
I ran all 3 in 3 different rooms and I controlled them using ROON.
I have 2 Rendu's and 2 DACs left. I am looking to sell one set of the Rendu/DAC so I can start saving up for a much more expensive DAC, which I will use a OpticalRendu to stream to.
BTW - Streaming via fibre is the way to go because it does not matter what is behind the fibre (glass cable). The glass kills the analog noise that resides in Ethernet cables.