I am also looking for a device for reading A4 formated pdfs. At a present time I found DR800SG could be suitable. Advantages of the WiFi technology are not combined with high res. displayed yet (at list at my knowledge). Anyway, if you know 8'' or bigger E-ink reader with wifi, please let us know. A a present time I am using PRS-505 - not really good for pdfs with vector graphics.
Thanks in advance for comments.
