Originally Posted by Mono
To my opinion, the issue is not of big importance. It is BW, so the defective pixel is not too much visible in real use (as opposed to coloured pixel on LCD). Also the pixel size is much smaller on e-ink than on LCD. It also decrease practical visibility of defect. And also we are used that print on normal paper is not always perfect and the paper itself is not always uniformly white.
At least in my case, it is a spot of roughly 3x3 pixels that keep the same color (either black or white; it acts roughly as an over-sized pixel). It is quite noticeable if it hits some character, but it is not really a big problem.