Kathryn and I got back from Costa Rica last night. We had a great time. I spent five days persuing my dream of learning to surf. After 5 days of being beaten and blistered by a 10 foot board and 5ft waves, I started to understand the mechanics of catching a wave, even if I couldn't do it predictably. I am slow learner when it comes to balance sports, but I am persistent.
I've forced myself to take one get-away-vacation each of the last 3 years, and I have found it well worth it. If your projects fold when you are away, more than likely they will fold anyway. It may seem cliche that working without rest makes you less productive, but it doesn't seem true until you get out of the constant work cycle. I can affirm it is true.