I have to agree with @magicknow and @stevensegal above. I’d like to share my experience, not sure it aligns with others who have used Roon… but here goes. I have been running Roon Server since its inception. Prior to RAAT protocol, I would agree, that several other players out-performed Roon for sound quality. Splitting Roon to core server and endpoint via their RAAT protocol made a significant improvement in sound quality. In a perfect world, Roon Core should not be sitting in an audio rack, as its main intention is a library management system. An optimized end-point is far more critical than the server. Within the past year, playing via RAAT to a Roon end-point (either Bridge II, SOTM SMS200 Ultra, or Sonore uRendu) with a properly optimized network, and running the endpoint on a good linear power supply - we cannot detect any difference in sound quality based on switching up the protocol between the server and end-point. That does not mean that each end-point sounds the same - far from it, they all sound different, easily detectable. Currently, the SOTM SMS200Ultra with linear PS >> Matrix SPDIF2 >> I2S into the DS DAC sounds superior to everything else I have. Every 12 months or so, I go back to J river, or a UPNP server on my dedicated server, and switch up the protocol… No change in overall sound quality. What I do get, is annoyed with the less than stellar UI / UX of the other apps. Back Roon server goes. My system is revealing, I can hear the impact that a different power cord makes on the server - albeit very slight, and difficult to detect 100% of the time, it is audible. As of 2020, in my main system, the implementation of Roon sounds consistent with everything else. If there is a difference, we cannot detect it. All this said, about 2 years ago, streaming from Roon Core via LMS protocol sounded slightly more musical and alive than streaming via RAAT. IME, this is not the case anymore. I have to agree with what others said, that sound quality differences boils down to the hardware implementation, network configuration, power supply on the renderer, Ethernet cable going to the render, etc.
I also think for PSA’s sake, the endpoint protocol doesn’t need to be binary. Meaning, PS could focus on Octave as an initial roll out, but implement the “Roon Bridge” or RAAT protocol into the upcoming endpoint. I.E it may not be there by default, but allow users to enable it.
I completely understand Paul’s perspective of being in control of one’s destiny, and as a manufacturer it makes sense. As a consumer though, I have never been a fan of closed systems. For personal reasons we have far too many Roon end-points here to switch, my only regret is not subscribing to a Roon lifetime membership 6 years ago ;-).