You're right that PDF doesn't FLOW well on eReaders. But OTOH, and this is more important to me, the other formats don't LAYOUT well. This is probably mutually exclusive, but as long as I set the page right, PDF is the only WYSIWYG format available on the Sony Reader, no matter what fonts, pictures, margins, etc. I set on a page. I'm not so concerned about zooming since I always use formatting that I can read comfortably at the standard small size.