1. Ports aren't changed randomly for no reason (cf. the Debian OpenSSL debacle). A port is just that--a port of a program to FreeBSD, not some attempt to incorporate it into a holistic user experience.
4. The BSD license means you can do what you want with the code.
5. The overall system is clean, simple and very well documented. Most of what you need to know is in the handbook or man pages.
The advantages are more evident for a server. For a desktop, I think BSD and Linux are both pretty awful compared with OS X, but FreeBSD is slightly less awful, overall.
Points 1 & 2 also apply to Source Mage GNU/Linux, and for point 5, man pages are good for most packages and for the system these days, there is a developing wiki maintained by the distro, and documentation that may be missing is made up for by the helpfulness of the people in the IRC channel.
Point 3 largely applies in that building every package you install is far more automated than in LFS, and most of the "spells" (ports, packages) are kept up to date regularly (Gnome included), and it's very easy to update any that may have been forgotten, or to add missing packages. It took me about 5 minutes to clone the mzscheme spell to "mzscheme352" for Arc use. OTOH you still have to deal with the behemoth that is the Linux kernel configuration. I cheated; I got hold of a Debian kernel and used it as a base for make oldconfig, later tweaking a little.
