No 6" reader will do a good job rendering PDf files, for reasons that have been discussed in many older threads. Also, there seem to be many ways to create PDF files, so it's hard to make a blanket statement.
I would not recommend any small reader for reading PDF files unless the files have been created explicitly for that size reader, not a common situation.
I don't think that any revision of software will give you a 6" reader able to do a good job with PDF viewing. I'm sorry, I could be wrong, but that's my opinion of the state of the technology right now.
|