Using one right now, I can say that the G4 iBooks are SMASHING. It is an absolute dream to use.
Although it's the low end one, I don't care, its still wonderful. My only problems have been Airport related.
But there is good news, having just been to Future Shop today (My dad went to pick up some CDs), I tried the keyboard on the G3 iBook they had left. I can say for certain that the keyboard on the iBook G4 is a heck of a lot better. Not quite the keyboard on the 12" AlPB, but really, really, really good.
I know a lot of people complained about the keyboards on the latest iBook revisions, which weren't quite up to par as the previous versions.
No stuck pixels, and near no problems here. The only thing I dislike about this iBook is that its not mine, but at least it is in my charge