the first instance of this is with the call of juraz dx10 bench,
buy the gts they said, the hd2900xt is rubbish they said, it will never compete with the gtx they said.
i went with ati to see for myself and thank god i did. let the nvidia backlash begin....
And this is what developers of CoJ have to say regarding the issue at hand:

In this message we would like to comment some disputable information that was recently published by nVidia and that is related to the DirectX 10 benchmark mode in Call of Juarez.

Before the arrival of DirectX 10, previous graphics APIs only allowed automatic Multi-Sample Anti-Aliasing (MSAA) resolves to take place in interactive gaming applications. This automatic process always consisted of a straight averaging operation of the samples for each pixel in order to produce the final, anti-aliased image. While this method was adequate for a majority of graphic engines, the use of advanced High Dynamic Range rendering and other techniques such as Deferred Rendering or anti-aliased shadow buffers require programmable control over this operation due to the nature of the mathematical operations involved. I.e. The previous approach using a simple average can be shown to be mathematically and visually incorrect (and in fact it produces glaring artefacts on occasions).

All DirectX 10 graphics hardware which supports MSAA is required to expose a feature called 'shader-assisted MSAA resolves' whereby a pixel shader can be used to access all of the individual samples for every pixel. This allows the graphics engine to introduce a higher quality custom MSAA resolve operation. The DirectX 10 version of 'Call of Juarez' leverages this feature to apply HDR-correct MSAA to its final render, resulting in consistently better anti-aliasing for the whole scene regardless of the wide variations in intensity present in HDR scenes. Microsoft added the feature to DirectX 10 at the request of both hardware vendors and games developers specifically so that we could raise final image quality in this kind of way, and we are proud of the uncompromising approach that we have taken to image quality in the latest version of our game.

"ExtraQuality" is a visual quality setting enabled by default in the DX10 version of Call of Juarez. In benchmark mode, "ExtraQuality" mode does two things. First, it increases shadow generation distance in order to apply shadowing onto a wider range of pixels on the screen, resulting in better quality throughout the benchmark run. Second, it increases the number of particles rendered with the geometry shader in order to produce more realistic-looking results, like for example waterfall, smoke and falling leaves. The attached screenshot illustrates those differences when ExtraQuality is disabled. ExtraQuality is designed as a default setting to reflect the visual improvements made possible by DX10 cards and is not meant to be disabled in any way.

All updates to shaders made in the final version of the Call of Juarez benchmark were made to improve performance or visual quality or both, for example to allow anisotropic texture filtering on more surfaces than before. This includes the use of more complex materials for a wider range of materials. At the same time we implemented shader code to improve performance on the more costly computations associated with more distant pixels,. Some materials were also tweaked in minor ways to improve overall image quality. One of the key strengths of NVIDIA's hardware is its ability to perform anisotropic filtering at high performance so we are puzzled that NVIDIA complains about this change when in effect it plays to their strengths.

Default settings were chosen to provide an overall good user experience. Users are encouraged to modify the settings in the CoJDX10Launcher as required. Using larger shadow maps is one option that we would encourage users to experiment with, and in our experience changing this setting does not affect NVIDIA's comparative benchmark scores greatly.

We are disappointed that NVIDIA have seen fit to attack our benchmark in any way. We are proud of the game that we have created, and we feel that NVIDIA can also be proud of the hardware that they have created. Nonetheless these artistic decisions about the settings of a game rightly belong in the hands of the games developer, not the hardware manufacturer.

Thank you and don't hesitate to contact us if you have any questions.