I couldn't find any real performance increases at lower resolutions (640x480, 800x600) in any game or application, no matter how high I brought it up with standard cooling. However, at high resolutions a couple frames were gained. Even after I attacked it with a 30Watt Peltier I could only get 8fps extra out of it at 1600x1200 only! Far less at lower resolutions.
Conclusion? Well I don't think the GeForce is worth overclocking unless you can keep the temperature below the shipping temperature. We already know that nVidia had to clock the GeForce 256 lower than they would have liked simply because of design difficulties. Even so, the increases yielded are at resolutions that are unplayable anyway (around 20fps at 1600x1200 overclocked to the max with peltier cooling). If you do want to do out-of-the-box overclocking without any additional cooling, tests with all GeForce cards currently in the FPS3D labs have shown that the Erazor X is the best overclocker if you must know.