In order to be creative, productive, effective, enthusiastic, and inspired we need downtime or me-time in between all the tasking we have become so accustomed to. Whether meditation time, gardening time, family time, beach time, hiking time, art time, poetry time - it doesn't matter. But it's better if it's right-brain time to balance all the left-brain thinking we do so much of.
This country has not been terribly supportive of the need for personal time because we believe that time is money, time is scarce, time is of the essence, time is precious, and time should not be wasted. Hence companies don't invest much in their employees' well-being through increased vacation time, and a culture of guilt has formed around taking time off to the detriment of our mental health (here an earlier related post - enjoy your weekend, really).
In contrast, most Europeans receive between four and six weeks of vacation time on top of all those long religious holiday weekends they have, while we have to scrape by with two lousy weeks unless you have built up serious seniority. But all these underlying beliefs depend on your perspective. My husband's company employed a young man for a few months who, before quitting, inquired if he could work part-time instead of full-time because he needed more me-time. He was willing to take a substantial pay cut in exchange. I think the younger generation is ready to take their time back. There is an actual organization, TakeBackYourTime.org, that promotes cultural change to that effect. Take note, it's coming.
If you are an employer you are in the enviable position of being able to experiment with allowing more time off and experiencing for yourself if it makes your staff more creative, more enthusiastic, more balanced and relaxed, and ultimately more productive. I believe that two weeks vacation with productivity at half-mast is a bigger waste of time than offering more time off and seeing your staff work at full throttle.