Letters and/or Digits
1. No screen refresh.
2. No "LCD eyestrain" after using it to read e-books since launch day.
4. Full interactivity.
5. Plenty of battery life for e-books plus other stuff.
I think "genuinely attractive" is the key here. After trying them, I wouldn't get an e-book reader -- the expense related to single functionality plus the look of the screen turned me off. It may be a small thing to some, but I don't like the refresh. Not I, nor three friends who have an iPad have experienced any eyestrain. Perhaps it's due to the ability to control font size and brightness on the fly. Or perhaps it was never there at all. I think it's also about experiencing it. The iPad comes loaded with the Winnie the Pooh book you see in the ad, and everyone has been immediately impressed upon seeing the full colour illustrations. Text is crisp, black is black, white is white, and it really feels like reading a book... the book fills the screen, and you're left with the book, and the gimmicky-to-some but neat-to-me fake book edge -- no distractions from a keyboard hanging off it or whatnot. Turn the device at any time, and you're looking at one page or two instantly. One only has to get the Popular Science application to understand what it means to see a magazine on the iPad. The experience is something totally different than any other on a mobile device, something non-existant and impossible on an e-book reader. PopSci is truly exciting on the iPad. Since, rather than wandering into the woods for two weeks, I come home every evening, I'm only worried about a battery lasting a day.
It weighs more, but I have gotten over that due to the experience.
I suppose the one thing I could agree on is that it's difficult to read in direct sun. I seem to have solved that by, um, not reading in direct sun. I shall re-evaluate this point when apocalypse kills all trees, destroys all buildings, and clouds become a thing of the past.