Exactly why should I ever use a BSD distro apposed to just running Slackware. I understand that BSD kernels are smaller in code making them a little quicker/stable and that the code is supposed to be fairly portable (no idea what to), but other than that what is the big interest in using BSD as a standard desktop or even server? Rarely have much trouble with Linux kernels or services...

FreeBSD has ports and other ports related tools which is its shining point.
Also, alot of stuff in FreeBSD just works. Not only does it just work, it works very well.

I just recently switched to FreeBSD for my desktop. Previously it was Archlinux (previously Slackware). Man am I loving it.

Technically, you're right, you don't really have much insentive to leave linux. But running FreeBSD makes you l33ter ;p. Besides, if you are inclined to using Slackware because of its UNIX bias, why not just make the jump completely and hop aboard the BSD-train?

FreeBSD may have its ports collection but building everything from source is time consuming and head wrecking! I hear it has a binary repository now, I haven't used FreeBSD since 4.4-RELEASE.. I currently use arch linux, it's got it's own "version" of BSD's ports(abs/yaourt) that works quite well but I tend to stick to using the binary repository.