It might help to know your main interest: bare metal server in a coloco? Virtualised servers? embedded? desktops?
Do you manage thousands/hundreds/a handful of machines?
Or is your interest entirely academic and structural?
I agree that most of the obvious Google searches return superficial comparisons of the installation process or explanations of the packaging and upgrade processes.
For virtual servers, I've found Ruby API calls to be excruciatingly slow on FreeBSD VM compared to Linux. I'm using TransIP as a VPS provider and although expensive I'm happy with them.
I used FreeBSD out of curiosity. So far, I'm using my VPS to run services (mail, vpn, etc.) and found FreeBSD to be stable, easy to admin and fairly secure. Another interesting thing are the tools. BSD tools seem to be easier to configure: e.g. PF syntax > IPTABLES syntax, or OpenSMTPD (OpenBSD's smtp server) vs virtually-everything-else.
Do you manage thousands/hundreds/a handful of machines?
Or is your interest entirely academic and structural?
I agree that most of the obvious Google searches return superficial comparisons of the installation process or explanations of the packaging and upgrade processes.