I think to sum it up on the screens, both the K3 and K4 have great screens. I probably wouldn't use the screen quality of these two readers to judge which one is the better buy. There are much more important factors to use in your decision. I make that last point based on the fact that both readers have comparable screens. Although I might think one has the better screen and someone else might think it is the other, we would agree that the difference is not that significant to be the sole deciding factor in which one to buy.