In particular they had a LG 22" display that only used 22 Watt at full backlight. It was not very bright, but it was fine for office or home use.
As they had a power meter attached, the power claim of 50% reduction was easily verified. At full backlight usage hovered around the 21 W mark. It also showed that it only used 11 Watt at the lowest backlight setting, where it was still somewhat visible.
They had one of the new 24" Apple LED Cinema Displays. An employee asked whether I had any questions, so I asked whether it was OK to move the power meter to the Apple displays to check out how much power they were using. Lo and behold the manager turned up, said yes sure. We set the meter up with the Apple display. The results were:
|0%||backlight off or almost off; not watchable||11 W|
|20 %||Normal office use||20 W|
|40 %||About as bright as the LG at 100%||30 W|
|100 %||Very bright||88 W|
I was amazed by the range actually. Certainly in that store the picture was usable at 20-30 W, meaning you can easily save quite a lot of energy by turning your screen down a bit.