I love my Paperwhite. My only complaint is that converting PDFs of programming books (or any books with text formatting or tables) results in some pretty unreadable code snippets.
Are there any e-readers that connect to an app store of some sort? Squashing an A4 PDF onto a small e-reader screen is a difficult process, and it seems like it would strongly benefit from competition between different rendering software.
Its really more of a limitation of PDF. It is intended as a static format based on layouts the size of a full sheet of paper. Its internal representation does not lend its self to layout changes. Most attempt to fit it to a smaller screen are problematic in one way or another.
It would be better to start with a document format that was always intended to be flexible, not fossilized.
You make a fair point, but on the other hand many pdfs have massive margins, or multiple columns, or can have text reflowed in a reasonable way. You can't use pdf readers for all circumstances, but with good software you could handle 80-90% of cases.