Have you ever tried scrolling with an e-ink display? Maybe the absolute latest ones are better but using the kindle web browser on my 2 year old kindle is an unpleasant experience.
What I'd like is probably something in between. Or one e-ink display and one 'normal'. But the OS would need to be aware that it was dealing with an e-ink display. You'd need to say goodbye to animations/flashing cursors and mouse pointers etc.