DFI = good OCing from what I've read. As someone else said, thats about it. You can go to DFI forums all over the web and read about BIOS issues and such. In my opinion, Epox boards are the way to go for excellent BIOS's, OC'ing, and layout, and just overall thought process going into the motherboard design and execution. They make MSI look like such utter garbage that you'd have to be totally uninformed and really a complete noob to even think of buying something they make when it comes out without getting some user experiences collected from various forums. On the other hand, I feel great about buying an Epox product the day its released knowing it will be well supported and generally work without any strange problems at all.
Some people think DFI's are now the holy grail, but I think a lot of that comes from Anandtech's massive coverage and promotion of their products, so much that I'd rather avoid them because it makes me sick when that kind of thing happens.
Now that I've contributed all the useful info you will likely get in this thread, let me just say I'm so tired of threads like this day after day:
"best 939 board"
"whats the best AMD64 mobo?", etc...
You'll be making a decision based on a couple stupid biased posts people make to your thread. Spend a little extra time and read more specific forums on the web that pertain to the motherboard you're interested in, see what the major problems/hurdles are, and then make an informed decision. Seems like Anandtech forums are filled with a bunch of brainless noobs posting redundant questions these days.