Today in amusing H2O review comments:
http://www.laptopmag.com/reviews/ereaders/kobo-aura-h20
"However, when I set all three e-readers' lights to 50 percent, the Kobo was so bright that it was distracting in a brightly lit room. In that setting, the Kindle offered the best reading experience."
Um. So? What matters is the range of the brightness, not whether the setting labelled "50%" is identical on two different devices.