Try this yourself.

Compare the reading experience of a PDF to that of an ePUB or other ebook-specific format.

I've recently started using Moon-Reader on Android. And ... it's pretty awesome. Text is legible, you can read pages without zooming/panning pages, text fluidly fills the page, graphics are supported, navigation is very fluid, controls are, if not "intuitive", very discoverable and stay out of your face.

Plus the whole application is designed for reading multiple books. There's a bookshelf, access to local storage (if you need that), and online ePUB libraries (OPDS format).

I've tried converting from other formats to ePUB via Calibre, and it's a bit hit-or-miss. It seems to be broken currently in Debian/wheezy. Under Ubunto 11.10, I may or may not get something that's actually converted, and the formatting can be really, really broken.

Oh, and in ePUB/Moon-Reader, if you leave the book or app and go back -- you're where you left off (as with a dedicated hardware eBook reader). Unlike every PDF reader I've experience on Android, where you start off again from page 1.

Sorry, but the mobile PDF experience is extremely broken.

Actually, other than printing to paper (or previewing same), the PDF experience is extremely broken. I'd prefer ePUB for pretty much all my documentation these days.

Constant zooming and panning for every page turn and no ability to alter the font, size or color. Sure, smartphones can render PDFs just fine, but reading long PDFs on small screens is just a miserable experience inherit to the format.

Personally I find that epub rearranges itself better for font size / screen size that a smart phone offers. PDFs are usually painful to read because you have to scroll the page sideways to get the font size I like.

But from memory the book is not image heavy, so converting to a text doc (or epub format) should be a very easy cut 'n paste, so the parent comment is a little bit on the ungrateful side.