How is the backlight affecting your eyes? I ended up buying a Kindle because reading on an iPad was straining my eyes too much, specially at bedtime.
Not sure which ebook reader you use but in Play Book there's "Night Light" which gives that f.lux-like effect. Definitely not as good as e-ink but it helps a little.
In daylight its fine and at night I just turn down brightness.
Screen is adequately large and the DPI is so high that they look great, it turned out to be a useful device.