I am using the cool 'automatically dim screen to save power' feature, which though doesn't work reliably.
What I see is the following:
- when you unplug the power cable, the monitor brightness is reduced to a default value, which is about in the middle of the whole brightness scale. In this situation, auto-dim seems to work fine, and that brightness value is restored when I e.g. move the mouse pointer
- I occasionally set the brightness level manually some steps down lower than that default, to save more batteries, and because my screen is quite bright itself. In this situation, the monitor auto-dims fine, but when I move the mouse pointer, the brightness value I manually set is not restored, and the brightness remains at the lowest possible value of the scale.