I have a DXG and it is great for pdfs. If you actually read those pdfs and don't need to make bookmarks, notes, or search through the file the DX is the way to go. I picked up my DXG via Craig's list for $230 with leather cover and reading light. You don't have to pay $379 if you have the patience to wait for a deal to show up.
Duokan adds pdf functionality that is missing from the DXG's firmware.