It's just referring to post proccessing effects like bloom, depth blur, motion blur and those type of things isn't it? Nothing different from any other game, they just call it a different name. Or am I completely wrong... I have it enabled and didn't notice a major degrade in performance.
Kuma 7750BE @3ghz(hopefully 3.4 before I get my new daneb) - 4gig DDR2 800 - 9800GTX+ (ver2)
Something up, my laptop doesnt have a noticeable drop in frames when I turn it on either, though I must say its pretty ugly effects in this game anyway so dont feel too bad if your getting a performance hit. I think I might turn it off myself.
With them on, you get jaggy lines during dialog scenes, yet the lighting is perfect. Without them, the lighting is WAY off and everything is too dim. Turning the brightness up just makes it look worse.