Ultra Detail, 4x MSAA Plus Transparent/Adaptive AA
If you want to address transparent textures without applying FXAA’s blurring effect, transparency AA is the way to go. Use Nvidia’s Transparent AA and AMD’s Adaptive AA technologies.
Keep in mind that these techniques are similar, but yield a different result. Nvidia’s TrSSAA causes a larger performance hit, but does a better job of smoothing foliage edges in this particular game when movement is involved.
At ultra details with transparency anti-aliasing and 4x MSAA, only the fastest cards like AMD's Radeon HD 6970, Nvidia's GeForce GTX 570, and its GeForce GTX 460 in SLI provide playable frame rates.