My top screen doesn't work correctly. Sometimes it freezes on a scene, and other times it will go black or turn off. The touch screen always works, even when the top doesn't.
If it frezzes on a scene or goes completly blank it sonunds more like your ds system rather that your top LCD
well it could be either one. if it turns black then perhaps the cables or wires whatever that are connected to the top screen are loose or barely working, partially connected and partially broken. but i would agree that a ds lite is better than a normal ds, if you have the money then sure go for it.