I think we use the idea of productivity to make ourselves feel better about doing nothing at all. For example, I feel better about sitting & watching a movie when I have my Inbox open. Why? Because I can feel like I'm multi-tasking, hence being productive. How satisfying.
Efficiency though, that's where the goods are. That's when we fulfill our tasks in the best way: top quality with the least waste of time and effort. My daily (and oh-so-satisfying) checklist helps me to be efficient! not productive.
My new goal? To live a meaningful, efficient, and satisfying life. Happy.