Ultimately, from a hardware standpoint -- and a pure reading experience -- there isn't a whole lot that separates the two devices. As I said, text looks sharp on both devices, with good contrast. But there are small differences. Interestingly, the Nook's screen feels very smooth while the Kindle's screen has a little more texture to it. I found the Kindle's touch-sensitivity more precise. By that I mean, single words were easier to select for look up in the dictionary and it was easier to highlight sections.
I can't say I really preferred one design over the other. I liked that the Nook felt a little lighter in hand -- and liked how it felt in hand -- but if you're not a fan of white borders, you'll be more attracted to the Kindle (the black border can help slightly with contrast perception). And the white can end up showing some grime from your hands.
I could delve further into the nuances of each device's design and operation. But suffice to say I'd be perfectly happy using either one and both the Kindle and Nook platforms have apps for smartphones, tablets and computers, so you can access your e-books across multiple devices without a problem. Also, both companies offer a selection of digital magazines and newspapers that are available on their e-ink e-readers. And both allow you to add e-books checked out from public libraries.
At the end of the day, however, even with Barnes & Noble improving its Nook shopping experience, Amazon's content ecosystem is still superior.
You can argue whether it's good or bad for the publishing industry or authors as a whole, but Amazon's cutthroat pricing strategy is certainly great for shoppers. Many e-books are just cheaper on Kindle versus Nook (and other third-party stores).
If you're an Amazon Prime member ($79 per year), the deal gets even sweeter. The Kindle Lending Library gives you. (Yes, many of them are obscure, but there are plenty of mainstream gems on there, including the entire Harry Potter series.)
Other Kindle niceties include(get the e-book version of a print book purchase at a reduced price); the ability to of a title for a few dollars more, and "Whispersync" between the e-book and audio version; and integrated "X-ray" and Wikipedia lookups (especially good for thick narratives like the "Game of Thrones" books).
Amazon is also touting some additional features that are coming soon.is a kid-centric program that helps parents encourage and monitor their children's reading, and it includes access to a stream of books for $2.99 per month. And Kindles will soon include Goodreads integration, so you can share book recommendations and highlights with friends ( earlier this year).
Kindle also has aoption that lets you send any webpage to the Kindle for reading later. Kobo offers similar integration with the Pocket app. The Nook doesn't have a similar feature at this time.
Finally, Amazon's e-book selection is just larger, with (according to Amazon) over 400,000 e-books you won't find from other retailers.
Barnes & Noble's strengths as a bookseller and recommendation/discovery engine shouldn't be overlooked -- it's good at it. But it needs to continue to offer up distinguishing features that are both useful and marketable to maintain the allure of its platform in the face of such intense competition from Amazon, which seems to introduce some new Kindle initiative or feature every few weeks.
In many ways, Barnes & Noble has done exactly what Amazon did with its second-generation Kindle Paperwhite. It's taken a good product and made it better, with a lighter design, improved lighting scheme, sharper text, and other enhancements, including the elimination of page flashing. Those are all positives, but I don't think the new Nook GlowLight brings anything so revolutionary or different to the world of e-reading that one might turn from being a Kindle customer to being a Nook customer. However, I do think the new GlowLight will help Barnes & Noble retain its existing customers and maybe even acquire some new ones who aren't ensconced in the formidable Kindle ecosystem.