I am using Roon ROCK (v1.5 build 363) on a NUC8 i7 (16GB RAM/SSD) to stream to my Roon endpoint (RAAT) dCS Rossini DAC via a Netgear GS108 switch. Music from a Synology NAS and Tidal. The NUC BIOS is tweaked (turbo off, speedstep off) and Roon reports a Lossless signal path (Fixed Volume, no DSP).
Compared to using the dCS streamer and UPnP renderer the sound quality is not the same. There is some treble harshness, a little less bass, sligthly less width and depth of soundstage and a small reduction of resolution. The differences are similar independent of sampling format or streaming source NAS/Tidal. To avoid exaggeration, Roon sounds good, just not as good as dCS on its own.
I have read the suggested Roon instructions, forums etc but currently I am not sure on how to proceed. I was under the impression it is possible to get similar sound quality using Roon (without resorting to DSP, upsampling or hardware optimizations like fanless, LPS, audiophile switches and so on)?