Curiosity about BSD

[shep]

I think the key is what is your goal?

If you want to learn I would recommend OpenBSD as the documentation to install, configure and populate with applications is concise and up to date

Slackware is in many ways similar although I do not think the documentation is as good. Slackware has the advantage that all software (not just the base system) has security updates
http://www.slackware.com/changelog/current.php?cpu=i386

OpenBSD used to have security updates for secondary packages but this was too much given the number of platforms supported by OpenBSD.

In my opinion PC-BSD is the BSD equivalent of SimplyMepis. You are likely to get a working KDE desktop but you will not lean much about BSD unix in the process.