I have read a few comments here and around the web which imply or state that people are finding the larger display on the KDX easier to read compared to the smaller size panels.
Could it be that the current eink panels just to not lend themselves to smaller form factors? I am thinking that the larger panels allow more light to reach the background and reflect more light back. As a result the larger panel either is or at least appears to be brighter/easier to read on than a 5" or 6" panel.
This is pure WAG on my part bit the comments I ran across here and there make me wonder.
I do not like the grey on the smaller panels, hence I do not like our K1 nor do I like the 505 and see no reason I would find the K2 an improvement. But even in video's I like the look of the larger readers like the KDX. My only thought is that because the there is more screen real estate it allows more light into the "equation" and even if the display is not actually whiter, it can appear whiter and offer better contrast.
I dunno, but thought it might be worth the discussion. Or do I need sleep and am seeing things?