I'm on the mailing list for PC-BSD so here goes:
PC-BSD: FreeBSD "under the hood", there is a PC-BSD layer, so to speak that includes the PBI management, user configurations and many very useful tools that help you configure advanced technology like pf (firewall ported from OpenBSD) very easily. The GUI of choice is KDE 4.x and the operating system (PC-BSD), is very easy to install and use. Kris Moore, the PC-BSD leader, uses his Dad as a test person when designing tools and installers.
PBI management is heavenly!
FreeBSD: It's a fork from the original 386BSD and AT&T UNIX code. If you install this, I hope you are familiar with UNIX CLI and the general structure of the UNIX file system. If you go this route, let me know and I can help you configure a FreeBSD desktop with gnome (or KDE) if you'd like. I'm running off of such a machine right now.