With a big enough monitor reading documents on-screen is - in my mind - quite pleasant (annotating them is another problem, of course). To get the most out of on-screen reading, be sure to do away with distracting stuff like window borders or, even worse, gadgets for printing, saving, etc.
A good start is add the following lines to your .mailcap
. They will make the pdf-reader start in fullscreen mode. On a 1280x1024 monitor A4 pages renders OK.
application/pdf; /usr/bin/xpdf -fullscreen '%s'; test=test -n "$DISPLAY"; description=Portable Document Format; nametemplate=%s.pdf application/x-pdf; /usr/bin/xpdf -fullscreen '%s'; test=test -n "$DISPLAY"; description=Portable Document Format; nametemplate=%s.pdf