It's amazing how freeing working only from 9 to 5 and not having access to emails away from the office is. I'm surprised anyone would willingly work that crazy
Past a certain point, I'm not solving issues -- I'm creating them. On any horizon over a week, I'm better off sleeping, eating, exercising, etc than trying to smash every hour into working. Keeping my brain on a routine and properly nurtured is more productive than crazy hours, by a wide margin.
But I guess looking busy can be as important as results.