It should be pointed out that OpenBSD is not UNIX certified.

You might retort that I'm being pedantic, but you didn't say that it offers "the UNIX experience". You said it offers "the UNIX(TM) experience".

https://www.opengroup.org/openbrand/register/

And it isn't just that OpenBSD isn't certified. OpenBSD notes where it deviates from POSIX and UNIX standards (For example: https://man.openbsd.org/sh.1#STANDARDS, https://man.openbsd.org/awk.1#STANDARDS).

You might retort with some "well, UNIX really means..." argument, but that's likely to come down to things like "I prefer or am more accustomed to where OpenBSD puts things or how its package management works or the way it does configuration." And that's fine. Arguing that a system has made better choices (or choices that work better for you) is wonderful.

macOS is actually UNIX® - but I don't think that what you're trying to get at is whether something is actually offering the UNIX experience. You're probably trying to get at something else - maybe a sense that there's fewer layers of indirection for things like how programs are actually installed and configured or a simpler, more standard layout across programs for things like configuration. But calling that the UNIX experience probably isn't the right way of phrasing it, especially if you're going to put a trademark symbol in there.

I would argue that macOS (since NextStep) is trying to bring unix pipes to gui via 'Services'. Unfortunately there is no integration with Spotlight (which would make apps like Quicksilver or Alfred obsolete).