I keep being tempted by the Aura HD because of the screen size more than anything, but overall, I don't think it'd be a big-enough improvement over my PW1 to justify it at this point. If I didn't have the Paperwhite, I'd probably have the Aura HD...
Originally Posted by HarryT
The waveform technology simply reduces the need for a full screen refresh. The real improvement is in the screen itself; the "Pearl" screen has greatly improved contrast over the Vizplex screen that the KK has, and the "Carta" screen is better still.
I'm pretty sure that the Kindle Keyboard (aka Kindle 3) has a Pearl screen.
I've gathered that Carta, while better, isn't as huge an upgrade from Pearl as Pearl was compared to Vizplex (that one pretty much meant that as soon as I'd taken one look at my then-new Kindle 3, my Sony 505 went to the nearest drawer and has stayed there since), but at this stage of eInk development, more gradual improvement instead of huge leaps is to be expected.