FXAA can be good for artistic visualization, where accurate colors and sizes are not crucial. I would consider risky to use FXAA for scientific visualization, as it alters the information: it blurs objects as if they had equal importance, while in correct anti-aliasing what is in front should never be altered by what is behind (unless it is semi-transparent).
For example, see discoloration in the purple line as it goes above green and blue background:
Discourse scales down the image in the post, so you can only see the difference in the zoomed-in red circles, or if you click on the image, download the full resolution image, and view it on your screen 1:1 (without any rescaling).