Highest available settings - LodBias -10, AA 16, AF 16, Alpha Masking etc.
Tested out with high poly weapons. Results: Clearer, sharper, way better than DirectX 8 and OpenGL and performs very smooth.
All the textures in the weapons are higher than 256 x 256 - and they seem to have no quality loss or resizings! This is apparent in the 3rd screenshot - the assault gun retains its original quality, while the other guns are much sharper. LOD loss doesn't seem to show (with other DirectX, a part of the gun would seem "broken off" if viewed from a distance)
Nice find.
EDIT: More screenshots. The first is a demonstration of the world textures and sharpness:
The second one is a comparison of OpenGL and DirectX 10. The comparison was made using an aim-down view of a weapon. The difference is very clear.
OpenGL:
DirectX 10:
