[parkher]

I have Aura HD with integrated light, but if I need a light I clip on Ozeri Flex on Aura.
So why I need that unnecessary layer then?

I don't know if you ever tried a really high quality light, like Ozeri Flex. But as I said - there is no comparison whatsoever. Integrated light is painful and unpleasant and the page does not look like paper at all - it looks like a LCD screen.
The clip-on light makes the screen look like real paper, pleasant and easy on the eyes.
Relatively speaking, of course. When you don't have enough external lighting.

Why anyone would want to use LCD-like lighting when you can have external-like clip-on lighting.
The answer is, I guess: convenience. Even the quality is so much worse.
But such harmful lighting should be used only in emergencies, not regularly.
So why not have a clip-on light for emergencies? BTW, clip-on light perhaps can be used more regularly - it is really far less harmful for the eyes.

I never liked the idea of integrated lighting, because it goes against the whole idea of e-ink - the screen should not glow because paper books do not glow.
But my eyes were really opened only when I got that Aura and tried its light and then clipped on it Ozeri Flex. What a huge difference! Fundamental difference, because the texture of the paper (i.e. screen) is completely different.

I read that Sony is also of the same opinion. That integrated lighting is so inferior and makes e-ink look so bad that they will never again integrate lighting into their readers.
I hope those rumors are true. Besides, Sony lighting is integrated into their covers - it is a pretty good solution. But the cover has increased dimensions, the 6" reader is almost like 6.8" Aura, therefore I don't like it. I prefer a clip-on light instead. Even though the integrated Sony light is more convenient to use.