Maybe Radeon only! Tested with AMD Radeon HD 7970-
This mods optimize Anti Aliasing for Radeons GPUs. Big Thanks to Fastmix! I just edited:)
Instalation: First backup your original FSAAProfiles.txt and FSAAProfilesDX10.txt. Then unzip and replace files in config folder. And its done. If you have enough powerfull card, enjoy 16xAA:)
note: DX10 has more optimized FSAA. Make sure you are running 1.2 version of the game;)
Video and info:
Youtube.com