I agree. Having the Oppo work with I2S would be ideal. I’m waiting for the upcoming PSA streamer, while pricey, will probably advance the state of the art and be optimal for use with the DS DAC.
I don’t have a microRendu, but I do have a pretty good Mac Mini sytem. Up until recently I had a solid USB chain including LANRover and nice Nordost USB cables. Then I got the UpTone LPS-1 which actually did tighten things up a little but. Not huge, but a bit. Things were a little more clear and crisp, maybe with a lower noise floor. Then I finally went for the Bridge II and hooked it up to my switch in a standard config. It didn’t sound significantly better, to my ears, than my USB chain. My buddy says he thought it was a little better, but I couldn’t hear it. Then I added optical isolation in between the switch and Mac and the switch and the DAC (powered by LPS-1). Now I thought the B2 sounded a little better than the USB, but not by much. Again, a little more punch and clarity with cymbals more realistic. Then I figured out how to direct connect my Mac Mini to the DS DAC via a “bridged” ethernet connection and upgraded to the Tera Grand Cat7 cables from the Blue Jeans cables Cat6a cables. Now I definitely noticed a significant difference in the B2 sounding better than the USB chain. I think this is mainly due to the direct connection since I didn’t notice a big step backward in putting the Cat6a cable back. For grins I also put in the optical isolation between the Mac and DS DAC, but didn’t notice any difference. From all this I have come to a few conclusions:
USB with LANRover is very, very good. As good, I think, as through a B2 connection through a decent quality switch.
Optical isolation is useful in isolating the DAC and PC/Mac from the switch. I got no significant benefit in isolating between the Mac and the DS DAC using direct ethernet connection, however.
Cat7 cables can be a significant benefit, especially if EMI/RFI are a concern behind your rack, like mine. Behind my rack is scary!
Direct, bridged ethernet connection is the ideal connection to the B2 from a Mac/PC. There are pages and pages of testimonials on this on computeraudiophile.com, mainly with micruRendu and SoTM sMS-200. It’s not the easiest in the world, but it can be done.
So what is my point? I think that if you optimize your B2 connection with good cables, optical isolation (+LPS), and direct connection, you will be 95% of the way to the best SQ short of using the I2S. I believe my setup would be competitive with an optimized microRendu with direct connection, FWIW. For that last 5%, I’m going to try the PSA server, Octave, with I2S. That’s been my experience.