If you want to use full-screen mode to read PDF documents on your OS X, I recommend using Adobe Acrobat 8. The experience is even better when you deactivate:
Preferences -> Full screen -> Fill screen with one page at a time. This will allow you be in “fit visible” zoom mode and really only see PDF document.
While you are in the Preferences, also check out other things as “Page display” and see if you prefer different kinds of Text smoothing.
Now back to reading all these papers..