Well, the 6600 GT isn't really powerful enough for Shader Model 3.0 to make that much of a difference. Now if you are talking about 6800GT vs. X800XL, then yeah, shader 3 is something to consider. However, the 6600 GT just isn't powerful enough to make heavy use of SM3 and get good framerates. Most people here are Nvidia fans, but I tend to look at both sides. I say get the X800GT over the 6600 GT.