As far as I can tell, the main benefit of jailbreaking is to be able to install a reader that supports more ebook formats, since a stock Kindle can already browse the web and read ebooks from any source, but it only supports MOBI/AZW3, and the Send to Kindle EPUB converter is not very good. But it’s easy enough to use Calibre to do a lossless EPUB -> AZW3 conversion without the hassle of jailbreaking. Is there some other benefit that I’m missing?