In our Sandra and Everest testing each board traded blow for blow. POV Beta and Real-Time rendering, and Cinebench 10 were slightly favoring of the WG board, as was 3dMark 2006.
HDTach was a trade off, as was Lightsmark. Fear was too close really, and Company of Heroes testing was virtually a tie as well. We saw the same trend in Call of Duty 4 and in Dirt 2, the newest benchmark we use on our systems.
Once we got to Vantage, we see the KG board outscore the WG in all but two of its included tests. Over all, there really is no difference to speak of. They are just that close!