I use obsd as a desktop system, I would not necessarily recommend this to anyone, you give up a lot, but obsd is my ultimate comfort system, it is small but full featured. I feel I understand the system far more than I ever did linux, which is one of the good guys. Compare to windows where despite using it my whole life I always feel I understand barely at all. But openbsd is so well put together I love using it, So I put up with the downsides and am quite happy with it as a desktop system.
Naturally I also use obsd as my firewall, a role I would recommend it in. at least if you don't mind a bit of old-school unix administration.
I have a freebsd fileserver and never got around to trying netbsd, But between fbsd and obsd I found I prefer obsd as the desktop system, it is a subtle thing hard to describe, but it feels better focused for desktop use than freebsd, not as performant and the filesystem sucks in comparison(thus the fileserver) but somehow feels better. I don't know.
For a firewall/router I use Ubuntu - it's what I use for everything else, so it's comfy.
I do believe OpenBSD is very very good software, but I do wonder if just given it's small install base if there are vulnerabilities simply nobody knows about. I guess may it doesn't matter since Linux is so much more widely deployed, perhaps that's just a better platform for hackers to spend their time.
OpenBSD exploits (defined as bugs in both OS and typically-deployed applications on top of it) are (or used to be) low-value but scarce and hence prestigious.
Linux exploits can be extremely valuable in monetary terms, but the attack surface is so absurdly vast these days, that they are seen as banal.
I am tempted, how do you deal with the non journalized filesystem?
This is the one "modern" comfort that makes me hesitant to try.