Is the new set of Dll good for a 9800 GTX ?

[Feuerfalke]

Yes, you can turn that setting on in the nVidia-Control-Panel.

(Rightclick on the tray-symbol in the lower right corner -> Start NVIDIA Control Panel (3rd from bottom).

Now in the window to the left: Manage 3D Settings
In the window to the right: Global settings.

Now to improve image quality:
Anisotropic Filtering: 16x
Antialiasing Gamma correction: On
Antialiasing Mode: Override application settings
Antialiasing Setting: 8xQ or 16xQ, depeding on how smooth you want your picture and what resolution you play at.
Antialiasing Transparency: Supersampling
further down:
Texture Filtering Quality: Quality
Texture Filgering Trilinear: On
Threaded Optimization: off (Some people report increased stutters in IL2 with set to Auto or on)
Vertical Sync: On

You can test if your game runs faster with "tripple buffering" enabled and "maximum prerendered frames" = 3. While Vertical Sync on is great for IL2 with TrackIR some other games tend to run rather choppy with it, so my settings posted are the best blend for different games running at 1280x1024 resolution.