By DAVID POGUE - The New York Times - Published: April 24, 2012
If you intend to buy an e-book reader, here’s a tip: First, spend an evening sitting cross-legged on a lotus leaf, surrounded by incense and sitar music.
The Barnes & Noble Nook with GlowLight is self-illuminating and its pages can be read even in a darkened room. 
Because buying a reader isn’t like buying a car, a DVD player or a hair trimmer. All of those tools are fairly universal. You’re not committing to one brand of gas, one kind of movie or one style of mustache.
No, when you buy an e-reader, you’re committing to that one company’s catalog of books forever, because their book formats are mutually incompatible. You can’t read a Kindle book on a Nook, or a Nook book on a Sony Reader, or a Sony book on an iPad. Sure, you can read Nook and Kindle books on an iPad, but when you buy an actual Nook or Kindle, you’ve just married its company forever. If you ever want to change brands, you have to give up all the books you’ve ever bought.
What makes this excruciating decision even trickier is that the e-book companies update their wares so often. If you have any doubt, consider the new Barnes & Noble Nook Simple Touch with GlowLight (or the B&NNSTGL, as people in a hurry call it).
This new $140 e-book reader is a very big deal. Until it came along, there were two kinds of e-reader screens.
First, E Ink screens. This is the kind of screen on most readers. The type looks like crisp black ink on light gray paper: there’s no backlight, no glare, no eyestrain. Not only can you read in direct sunlight, but that’s actually where the print looks best.
Battery life is fantastic, too, since E Ink draws power only when you turn a page. (It works by drawing millions of black particles into a pattern of letters by a brief electronic charge. Once there, there they can stay forever without drawing power.)
Pogue's full piece at The New York Times.