no idea how far this will reach but let's try:
if I were to start learning more about one of the listed BSD operating systems, which would you recommend? Guessing the answer could be different if we're talking about daily desktop usage vs server, so maybe clarify your answer via a reply if you can (fwiw, probably more interested in daily desktop usage, but open to whatever too).
Follow
I prefer GhostBSD myself because it saves me from having to install Mate after the OS since ot's preinstalled on Ghost. If that weren't an option then i'd pick OpenBSD because security matters most to me next to privacy.
