These days the Calibre project embeds a number of great conversion projects and adds its own valuable conversion contributions to turn PDFs to e-reader formats and still do a decent job of preserving layout (a ways to go to match Acrobat's conversion of PDF to MS-Word, but steadily getting there). Take a look at how it manages with your selection of PDFs, and see if they work better on your DX if you still have it hanging around.