MFAA is essentially dead since it relies on MSAA, and MSAA doesn't work properly with deferred shading, which most modern games use to look nicer.
Also, I'm pretty sure ESO uses it's own AF, since the setting is listed in it's usersetting file.
I just did, and it's like getting a free upgrade. I also enabled mfaa, not sure if that did anything but regardless, the game looks incredible now.
Get that option enabled, and have fun.