[SEE]

Looking at your system specs I would imagine that CloD runs pretty well maxed out with the in game AA enabled. I think the FXAA is a worthwhile option for those of us on low end systems who want to save a few fps hits with stock AA enabled.

Given that there will be an update that is supposed to include changes to the Graphics - I would wait. I am not sure its worth the hassle you are experiencing given that CLoD works OK without FXAA. You could tear your hair out getting it to work and then be disappointed.