No one would reasonably suggest that the DXG is a good reader for complex, multi-column PDF files. However, it is my favorite for books. When my Irex's screen developed problems I saw no way to go back to a 6" screen, so I got a DXG for $259.-. Well worth the price for me. I do think they won't find many takers at 379.-.
Anyway, there is no "good reader" for PDFs on the market right now (unless you are ok with LCD screens).