Hi,
I have a Onyx M92 (9.7") and I read many technical PDF files. It's possible to read this documents with a 6" or 8", but really, a bigger screen is an advantage.
I crop the file (with the Onyx's PDF reader) and I can read in portrait or landscape mode. Now, I'm reading the user guide for Beamer :
http://www.ctan.org/pkg/beamer in landscape mode (I've just changed my glasses and I prefer this for the moment) but in landscape mode is good too.