I am not qualified enough to answer for NT and BSD (I only can note they appear very stable nowadays). But XNU is not much better than Linux. It has a schizoph

I am not qualified enough to answer for NT and BSD (I only can note they appear very stable nowadays). But XNU is not much better than Linux. It has a schizophrenic soul with its BSD and Mach duality for everything. It is bogged down by Apple's never-ending "security" lock down efforts. It has no equivalent of "jails/containers". And, again, it is practically unusable for anything that is not created by Apple and is not extendable now that they are phasing out kexts. I think a very interesting recent effort in kernel architecture innovation is Fuchsia.