Kindle has absolutely no broken word problem with txt (of course), and I believe Story (as well as Cover Story I should add) is the only ebook reader on this planet having problem handling English text files.
In the PDF department, Kindle's great. It allows zooming, fitting to screen-size, and auto-cropping of white spaces. In addition the contrast is also adjustable, useful for those light prints. It won't do text reflow though.
Using Story for so long, reading with the Kindle is like a putting on a right pair of spectacles for the first time.
And the battery life! For Story, it lasts at most 4 to 5 days if I don't turn the power off, even if I don't read much. But for Kindle, it's able to conserve battery power in sleep (screen-saver) mode. After 4 days, the power is still at around 90%, with a lot of reading. A world of difference.