Optical vs Ultra Rendu.

Is it worth the $696 more to go with the optical Rendu:


Over the standard (ethernet connected) ultra Rendu:


Has anybody compared these units, is there a notable difference in sound quality between these two?  Both still connect to the DAC via USB. 


I have a BlueSound Node 2i.  Would this hook up to my BlueSound?  Has anyone done a true blind test?  This would require someone to change the connections to do an A/B comparison without the listener knowing the source by doing a random switching back and forth.  Try to stump the listener and then tell them which connection was what.  Some of these expensive add on little noticeable difference.  Kind of like splitting hairs in my opinion.  Which is more noticeable, upgrading speakers or amplifiers or using this add on?

the central idea of the optical rendu is to convert the audio signal into optical and then back to electrical just before sending it to the dac, such that any electrical noise on the ethernet fed electrical line is left behind

so of course, using any properly functioning fiber media converter to do the job will accomplish the objective

of course it is then key, on the receiving end of the signal that there be very quiet, noiseless power supplies used, so that new noise from such things as switch mode power supplies are then re-introduced into the music bearing signal

Thanks all. I have been researching a digital front end for some time now, sort of the last piece of the puzzle for me. It really seems this SGC bundle is something that checks all my boxes. My last hurdle was just trying to make the final call on the Ultra or the Optical. From what most of you are telling me here, it sounds like the $700 upgrade would be worth it. 

Another vote for Optical Rendu.  Here’s another product I just saw.  Interesting that it actually throttles down the speed to reduce noise and not too expensive.  Just another option...