>The trick is to have a way for developers to power down somewhat. I'm not sure how you would do that. I never got the chance to figure it out.

When it's time to change pace one of the things I think helps "power down" is to let team members work on things they are interested in or find important. Instead of priorities coming from up high it lets their minds breathe and explore something on their own. The difficulty is in managing to find the time for it.