If I could just have a half hour conversation with each student about their paper instead of trying to assign a letter grade and justify it in scribbled notes, I would be infinitely happier. I think they'd learn more from an actual conversation with me about the paper -- and I would mostly be asking questions, rather than telling them things. In my ideal world.
(474 students, if any of you happen to be reading this, don't panic. Yes, I'm grading your papers, but so far at least, they're pretty decent. I'm experiencing frustration with the grading process, not with you or your work!)