Do Streamer only devices really impact sound quality?

Simply put…

they can all sound different from one another. If you cannot hear the difference between one streamer and another, then it could be a question of the associated equipment? But even a low cost system should reveal the difference.  I used an Allo Digione with Volumio as the OS. I thought it sounded pretty spectacular. Especially with the coding mods and upgraded ps.
Then, I upgraded to a Pi2 design Mercury Streamer. My mind was simply blown by the improvement. It was immense. My system was instantly elevated (and it’s not all that special a system). To the point that I had serious trouble staying away from it.

So my answer is that there can be a major difference between transports.

Correct. Bits are bits. And jitter in today's equipment is so small it cannot possibly be audible. And error correction has been perfected for decades. Even as far back as when I was doing network programming for banking systems in the 80's.

@dvdgreco , There is no doubt that adding a good quality streamer to a good system will make a big difference.  It is likely that the Node and the Cambridge are not all that different.

I added an Auralic Aries G2.1 in front of my already good sounding Tambaqui DAC and it made (to me) a noticeable improvement.  I did not want to believe this, as there is a good streamer in my Tambaqui.  But it did.  I use USB from streamer to DAC, and also enjoy the Muon Filter in front of the streamer.  I also upgraded my network cables to Supra shielded Cat 8.

@soix ​​@tk21 Speaking of Darko, on the other end of the spectrum, here he calls the WiiM Mini "Outstanding" "Fantastic" & "Favorite streamer of 2022" all for $79.

https://darko.audio/2022/11/introducing-the-wiim-pro-network-streamer/

@navyachts Just as he did with the Sueezebox, he left out the qualifier “for the money,” but he did say it’s not on the level of better/pricier streamers.  Just highlighting a few words from his review without context is misleading.