Just looked into this and - this isn't e-ink just a grayscale LCD - at that point just get an iPad instead of an overpriced low end Android tablet.
Our mileage certainly varies - I would not consider buying an iPad (I already have an iPad mini and don't want more of that), but this device I really like. It's hard to put a finger on it. I read other reviewers claiming that reading e.g. X in greyscale is less addictive, and I didn't really believe it until I tried it myself. Something is certainly different about my workflows on this device.
Reading it late at night is much more enjoyable than reading an iPad, even with the Night Shift on.