I actually ran FreeBSD as a "desktop OS" on more than a few IBM Stinkpads for years. It worked well, driver support -- well, wifi was always fun, but if you knew enough, you could get them going (orinoco cards for the win).
That said, I never saw FreeBSD as anything other than a Server OS. So I wouldn't say the "desktop" comparison really ever fit in.
My experience with FBSD on the Desktop was always polarizing... when it worked well it was FANTASTIC, way ahead of any linux distro. Great drivers support, no bullshit with audio, 3d graphics worked great, etc. Really good.
If it worked.
If your hardware didn't fit inside a fairly narrow box (e.g. Nvidia for graphics), things failed horribly.
It's been a long time since I gave up on FreeBSD on the desktop, but I think back in 2000 I had some bad problems with whatever SoundBlaster card I had (some Audigy thing) and ATi acceleration just wasn't going to happen. But otherwise, it was rock solid. I think from there I went to Gentoo since portage was similar to the ports system.
I did try some of the FreeBSD desktop variants over the years (DragonFly and PC-BSD). But then you're still not quite running FreeBSD. I haven't kept up, but it looks like DragonFly is its own distinct BSD flavor now.
Yeah, the Audigy cards were always flakey (under Linux, too, as I remember). Support for the Soundblaster-series cards was much better.
The sound was really good for the time if you had a supported card, real hardware mixing, /dev/dsp (or was it /dev/audio) that multiple processes could write to and it was seamlessly mixed. Using the commercial version of OSS, as I recall. In Linux at that time you either had the open source fork of OSS (which wasn't nearly as good), or raw ALSA, which was promising but buggy.
That said, I never saw FreeBSD as anything other than a Server OS. So I wouldn't say the "desktop" comparison really ever fit in.