The
E-book Reader Matrix has a row for PDF Capabilities. As you can see, the PRS-300 has only "basic" PDF support. Probably the best is PocketBook (360° or 301+) but these only have 4 grey scales (in hardware), the EZ Reader's (Hanlin) are also ok for PDFs and the Pocket Pro has 8 and the forthcoming EZ Reader Plus (Hanlin V3+) has 16 grey scales. I guess I would go with the EZ Reader Plus, for its good balance between features and price. Note that a 5" or 6" EInk screen isn't optimal for PDFs (unless they are explicitly formatted for a small page size), but the larger screen devices are very expensive.