Posts: 2,309
Threads: 116
Joined: Jun 2005
I own several e-ink devices, and while the stuff does have a power advantage over LCDs (under some circumstances), and possibly other advantages, contrast ratio is NOT one of them. The best you can currently get with the stuff is black on medium grey. It's fine under bright illumination, but I find that under typical room lighting that a good reflective LCD (e.g., hp 50g) is more readable than e-ink.
It is also extremely slow to update. Even the newer e-ink that is supposed to be faster than the previous generation is still extremely slow. I think if people had a calculator using e-ink they'd be very likely to complain about it. I'm not talking about animation, which would be impossible. Just pressing a number button or ENTER^ would take a noticeable fraction of a second for the display to update, vs. the nearly instantaneous update everyone is used to having with LCD (and with LED before that).
I expect that eventually e-ink technology will improve to where it has a good contrast ratio and fast refresh, but it ain't there yet.