I think people respond well to natural rhythms with contrasting phases (a time to sow; a time to reap...) so I find the general concept quite appealing. One thi

I think people respond well to natural rhythms with contrasting phases (a time to sow; a time to reap...) so I find the general concept quite appealing. One thing that always bothered me a bit about scrum was that it's basically an endless series of sprints. Just saying it like that sort of illustrates the problem that you can't sprint indefinitely. Additionally, I've found that for maximum creativity/productivity, I need periods of down time. Work on a problem, then put it down, and often the solution will pop up while you're in the shower or taking a walk. So I think explicitly building some sort of breaks ("take a couple of days to learn/rest or work on whatever you want") is a good idea. I'd advocate doing this informally when needed or when schedule permits, rather than formally scheduling 3 on, 1 off.