If the OS needs to be practical for daily use, I would vote for OpenBSD because it's very usable. I has easy installer (just point it to free space) and select all software sets. The binary packages also get updates. Also, the docs (FAQs) are great!
Note: some *BSD tools (like fdisk) are much different than their GNU/Linux equivalents.
Some man-pages of interest:
* https://man.openbsd.org/afterboot
* https://man.openbsd.org/sndio + other related man-pages
* https://man.openbsd.org/man1/pkg_add.1 + other pkg_* package management tools
* https://man.openbsd.org/man2/pledge.2 + https://man.openbsd.org/man2/unveil.2
* https://man.openbsd.org/syspatch + https://man.openbsd.org/man8/sysupgrade.8
* https://man.openbsd.org/man8/fw_update.8
Has anybody used OpenIndiana? Is it usable as daily OS?