the WoW performance article piqued my interest today since i play WoW pretty regularly, specifically the part about wow performing better on DX11. one of the cards tested was a 5870, which happens to be one that i own.
Are you using the same driver revision as them. And have you reset the driver for performance. Make sure your not forcing any IQ improvements.
Is your game patched to the same revision.
I don't play wow.
im using the lastest driver, and as far as i know it is the same one they used to conduct their tests.
they are on a beta revision of the game, however all of the changes to the graphics engine have been implemented to the live version of the game a few weeks ago.
im not entirely sure what IQ is though. i only installed the ATI driver i didnt install catalyst control center, so i think any extra settings are turned off by default.