Do all STREAMERS sound the same when Streaming direct to Devialet expert

[hardcore]

I don't know about Zen, I am planning to check ROON Nucleus first.
Roon Nucleus has Air implemented API  as ROON Ready so I will use it directly.
I am not aware of any other streamers that have the same implementation.

You are currently using Roon Core on Mac Mini, and I assume Mac Mini and Devialet are connected to an Ethernet RJ45 switch, is this correct?

IMO changing to a Roon Nucleus will not significantly change the sound quality, if you keep the same network configuration and use the Nucleus as the Roon Core and stream directly to the Devialet's AIR/RAAT receiver.

Using specialized streaming endpoint or "Roon Bridge" like the Zen Stream will change and could improve the sound. In this configuration, the Zen Stream connects to the Devialet using USB or Coax/AES inputs and acts as the Roon RAAT receiver on the network.

Comparing the Roon Nucleus with the Zen Stream, my friend was using a Roon Nucleus connected over USB to a DDC (Singxer SU-6), feeding his DAC. He later replaced the Nucleus with a Zen Stream acting as Roon Bridge, connected to DDC and then to DAC. This sounded better than the Roon Nucleus acting as Roon Core and directly connected to the DAC.

Remember that the Roon Nucleus is basically an Intel NUC motherboard running custom firmware with a CPU and SSD powerful enough to run the Roon Core software and library. Compared to a Zen Stream or OpticalRendu which is built to act only as the "Roon Bridge" connected to the DAC, and as such is designed to minimize electrical noise and improve clock jitter performance.