Chuck Martin has another work-life article at Darwin. Busy as Bees talks about the importance of having the right balance of busy-ness in life. Here's the conclusion:
People at work tend to take all the time there is available to complete a task or a set of tasks. A small number of tasks will tend to get accomplished in the same amount of time that a much larger number of tasks takes by the same people in the same organization in the same situation.
However, accomplishing more within the same amount of time can be much more satisfying to the individual who really does know when he or she is performing up to their personal limit.
When very busy, the result can be businesspeople operating at the top of their game.
The article also warns about being overloaded. Essentially, there is some sweet zone where you are doing the right amount of work: not too little to make you bored, and not so much that you are swamped and working 15-hour days.