An update on my K4 purchase. I tried my replacement K4 in all of my usual spots and was disappointed enough to return it for a refund. I really thought I would keep it, but I decided to push on with my K3. I really liked most features on the K4. I'll wait and keep an eye on things and see if Amazon comes up with some kind of an improvement. Not 100% out of the market yet.
I did read a little about how E-ink works and will suggest a theory. Since the K4 is smaller and thinner Amazon asked for a thinner e-ink panel design, which reduced the number of black/white microcapsules, resulting in less contrast.
Second theory: The battery is smaller and less powerful so the panel is not being driven as hard (pulling the microcapsules up or down) in order to extend battery life.
Beaker will be in the lab checking this out.
