Reading modes: iPad versus Kindle

iPad: Skim content, go back and forth quickly. I’m in this mode when I read technical books that teach me something. Then the Kindle’s display is too slow.
Kindle: Calm sequential reading, no distraction. I’m in this mode when I read fiction or more narrative non-fiction. Then I don’t want to be tempted by web and email and don’t want the slightly eye-straining backlighting.