My VisionTek GF4 TI4600 cards are overclocking better with the 27.51 drivers (320/355) than with the 27.42 drivers (315/345). The higher overclocks hold true in both 3dMark and games. I am running tests on the 27.70 drivers right now. I have noticed most of my games seem smoother with the 27.51 drivers but the colors seem better with the 27.42. OF course my eyes are getting old. 