Good article.
One of the great things about having an open platform like the Xteink is that it should uncover loads of novel and unsatisfied use cases. Eg, this could be paired with a mobile phone to act as a secondary display much better suited to outdoor applications in bright sunlight.
working on an daily life ePub generator (because I want to stick to CrossPoint) with the opposite goal, namely use the phone as little as possible, but I admit I would also like to tinker with an additional temporary display, at least for typing