Each of the BSD's have their own personality and group of adherents. There is a secondary circle that may love all BSDs. Long ago there was east coast unix and west coast unix. The BSDs represent the West Coast thread.

I just like the BSDs because they all maintain a single document that can get you from a single system host install to a supporting network installs DHCP->TFTP install.

I always go for either NetBSD "We install on anything" or OpenBSD "We are still just trying to get secure implementation of the 4.4 spec"

I’d love to read more about the differences in “personality” among the BSDs. Any suggestions on material to look at?

Not exactly what I was looking for, but it’s the only thing on offer, so.