I know everybody has been eagerly awaiting an update to my situation, but I think I may have solved my BF3 crashes. For whatever reason it seems to have been an issue with Adobe Flash and Firefox, and how that was integrating with the BF3 browser. During most of the crashes, but not all, I would get an 'Adobe Flash has stopped working' error in Firefox, but I was assuming that it was a symptom rather than the cause. I even reinstalled the latest version of Flash and it still did it. Then to try something different, I uninstalled Flash and reinstalled the Internet Explorer version of Flash (Active X) and started using IE to run the BF3 browser. I've now gone crash free for about 4 hours, which is really long.
But that's not to say I think the 320.18 drivers aren't still f'd. That was the only time I've ever seen artifacts on my 670, and since rolling back the drivers I haven't seen any more. I'm still advising all my friends to not use the 320.18's.
In more positive news, I received my Fractal Arc Midi R2 case in the mail the other day. So sexy. Now I just need to wait for my additional fans to arrive, which unfortunately I had to order from some really slow-ass companies. Hopefully get those next week and then I can start the build.