Larger -> bulkier -> more difficult to hold in my hand while reading - actually I think they are worse suited to read when formatting is not an issue.
So for novels (text only): 6" or even 5"
For PDF or anything with pictures, spreadsheets etc.: 8" or bigger (just like in case of books - you do not see many paperback size documentations).
Last edited by worxland; 06-16-2009 at 02:37 AM.