... I am 100% streaming these days.
could you tell the difference between the Mac and Aurender in a blind test?
I could definitely tell they are different.. Subtle but different. I would have to really listen to try and point out exactly what is different about them though
You might already be close to squeezing the out the highest quality streaming has to offer. I had Tidal's HiRes streaming service for a year, my best description of the sound is meh. Not bad, kind of like average FM radio, which is how I listened to it. Tidal's sound quality compared to ripped CDs or hi-res downloads always came up lacking. That was a couple of years ago when Tidal was doing some secret strange MQA digital manipulation in the background, maybe Tidal's HiRes FLAC 24bit, 192kHz streaming is better now.
Even the highest quality DAC and streamer can only do so much with a compromised source. The old Tidal attenuated the lowest bass (my REL sub went down to 20 Hz) which meant room ambience and space was missing plus highs were less sparkly and crystal clear. The reviewers in Stereophile use streaming to evaluate new equipment but maybe they have to, if they only evaluated equipment using only high-res sources then readers would ask about streaming.
The Aurender N50 has Triple-chassis Architecture (Server / Power / Audio), Ultra-low jitter and precise timing & multi-layer AC and DC filtering, and Galvanically isolated audio class USB 2.0 output module. All that makes a difference in a music server that plays flac and hi-res music downloads. I upgraded my DIY server slowly over years and could hear the improvements those changes made. Tidal was long gone so any comparisons would be guessing.
And even after all my improvements on the digital side, the biggest improvement that could be heard by everyone without guessing was switching out to high end RCA and USB cables. You might be there already, I wasn't and the improvement in clarity, smoothness, 3-D space and depth was a revelation.