I was bothered by a nagging suspision that because of the posts here, there is some truth to this, so upon further testing I have found a senario where this actually becomes almost true...!
When you have your device no more than 10 inches from your head, in a almost totally dark room(nightime)!
What makes this more noticeable than most other PDA screens (yes many other PDA screens do same), is that the Asus has a more brighter, straighter beaming light than any I know... My Asus 730w is brighter at half setting, than my Toshiba e755 at full brightness!!
Add to that that the light seems more directional, and you can get this senario...
Also, it is known that the Loox has the widest viewing angle, similar to the HP4700, so when you compare to the Asus, there will be a noticable difference...
But I still do not think it is a problem... just dont hold it so close, or have it too bright.
Also, with light off outdoors, this problem doesn't exist.
