(Granted, the out of box behavior and the achievable latency are two separate issues)
(Granted, the out of box behavior and the achievable latency are two separate issues)
I have never seen a mac box achieving reliable lower latency than Linux or Windows on the same hardware. Macs are nice for the plug'n'play experience - even though more often than not you still want to install your soundcard's driver.
But when it comes to doing actual work... https://www.dawbench.com/win7-v-osx-6.htm
If we're talking pure latency then UA, Focusrite, Apogee and Avid have lower RTL for the same buffer size in macOS. RME is identical on both platforms and I'm unsure about antelope.
Regarding loads before under-runs that's a very tough thing to test, as it varies between products. GENERALLY: Comparing Digital Performer between platforms heavily favours macOS. Comparing Pro Tools favours macOS (currently). Comparing Reaper favours windows slightly. Cubase favours Windows... etc...
There's also load type that factors in, as with macs you get a specific build with minimal leeway. Windows builds can be planned for a given build (highly serial, highly parallel, RAM hungry, Latency performant etc...). It's not too hard to build a test suite that favours macOS everywhere on the same machine, likewise for Windows.
But to the original topic, latency, macOS is generally superior in this regard when looking at RTL specs for the same device.