The core has mostly been reliable for me on macOS, at least the standalone one without the UI. The rest of Roon, though, not so much.
Some of the issues I keep having with Roon are the same Mono/.net/C# issues you have on all platforms (like it being the outrageous memory hog that it is, constant crashes on mobile devices, or the fact that the UI doesn't act, look, or feel native to the environment it's running on). Others are just bad design decisions on Roon Labs' end, like the fact that ARC almost never actually works, and when it does, it doesn't do so for very long.
And yes, they keep having regression problems, which is just … sad.
Today's issue: The Roon client on my workstation refuses to recognize any and all DACs connected to that workstation. macOS recognizes them, other applications (like the Qobuz app) recognize them, just not Roon. I've had the same issue a few weeks ago and tracked it down to another USB device that was connected to the machine at the same time, but that device isn't connected today. Even if I unplug everything but the Gungnir MB and reboot the entire machine and every and all Roon instances on my network, it still doesn't want to recognize any DAC locally connected via USB.
But just on that one machine, others work fine.