Note to Drago:
Remember it is not always necessary to use up every character they allow--to use a cliche, "quality over quantity." If after 4000 characters you feel you have a good, complete essay, send it in. Its doubtful that the people looking over these essays will read them word for word. If you add 2000 characters of useless filler, and that is the third of the essay they read closely, then, well, you're screwed. Sometimes making it a little shorter will actually impress them--you may stand out a little better. Between the two AMCAS essays, I think I had at least an extra 2000 characters left over, and that was after adding more than I thought they should. But that is just my opinion.