Same card i have. Had horrible stuttering all weekend as well as horrific FPS drop that would make the game run like my system was gonna explode. Only way to fix the FPS drop was to alt tab out of the game. Nothing fixed the stuttering except for Xophers recommendation of running it on Standard settings.
Im not all that concerned about benchmark scores once the stuttering isnt there. Did you notice the stuttering during the benchmark or from trying another game?
I would be interested in knowing if the performance gains people are having are just from Crossfire users? From what iv read on Reddit this patch was more focused at Crossfire users!