10% bump in average fps with heaven (in the case of my OC'd card it went from 35.3fps to 38.7fps [1680x1050, 4xAA, 16xAF]), and the points of heavy tessellation have benefited the most, closing the gap on the fermi 'benchmark' by between 20-60% in the heavy areas. All that in one driver!
However, i've had no dirt 2 performance increase using the in game benchmark, but it's very obvious to see it's handling the crowds far better, plus it manages to stay above 60fps to stop double buffered vsync from screwing me over and going to 30fps. So the benchmark seemed to have lied somehow. I need to redo it at some point