I STRONGLY recommend the DFI Expert. It's the board I use, and I had to decide between the same two models. I work in a PC repair/sales shop. Of the new Asus boards, 4 out of 5 that we received in our first couple shipments were sent back to Asus, DOA. Ever since then, about 1/2 of the boards that Asus sends us is DOA. If you talk to other techs across the country, they all say the same thing: half are DOA and many of the rest die after a couple months of usage. Asus usually makes a rock-solid performer (I've owned 3 or 4 of their previous mobos), but this latest generation of boards is nothing but problems, really.
The DFI has been very fast and really reliable since day 1. No problems, no issues, just awesome performance