I have the new screen on the DXG. The background is not white but the text is more crisp and darker on the new screen. I think that the new screen is nice but I can't say I noticed a huge difference when I moved to my K1 for my beach vacation. I didn't want to risk sand and water getting in the DXG so I used the K1 with a water proof cover.
Perhaps I am in the minority but I don't think that the new screen is a great reason to buy the K3. It could also be that I am 38 with good eyes (well crappy eye sight but otherwise healthy eyes) so that I don't notice the difference as much as someone with older eyes.