I have had three of the readers in your title and I have found after a year that I hate touch and the original nook is much, much slower than the Kindle 3 and has more bugs and lower contrast, so that one went in favor of the Kindle. It took me a while as I really liked the nook and I really didn't like the things the Kindle was missing (.epub, library books, easy replace battery, SD card).
Between the Libra (essentially the same as my JetBook) the Kindle has much better contrast, but is a bit bigger (can be a plus or minus). I enjoy reading the Kindle much more than the JetBook, but the JetBook has massively superior file management. It basically uses the normal Windows file system. It also has no trouble at all with large numbers of files (1500+) and does not slow down like the Kindle. However, those dummys still use USB 1.1 so transfer is slow and buggy. The JetBook needs an SD card and I consider it a strong plus as a crash in the reader will never cost you any books. Backup copies on another SD card are cheap and easy. It also can access epubs from the library and a ton of other formats, while the Kindle 3 will have to wait until the end of the year to get library books.
Kindle has nearly twice the market share of the nooks and this shows up in the availability of after market stuff like batteries. I would expect that I can make use of it long after B&N moves into something different. Amazon has much bigger pockets when it comes to development and support.
For me, the nook is dead. Their new version is a really stripped down model and I don't trust them to do things right. They made some major mistakes in their firmware and just don't seem to get it. The Kindle is my favorite reader and I read 20 books at a time. However, my Jetbooks will probably outlast anything else as they use AA batteries (not so for your Libra) and support most formats.
At $114 for the Kindle, it is hard to see how anything else make any sense, unless you are in love with touch or want something specific that Kindle just won't do.
Last edited by chas0039; 06-18-2011 at 08:09 PM.