The Duckboards were needed due to my first mistake. You can't see from the photos, but the workbench is on top of a raised floor. The floor is raised about 2" for the the back 3' of the garage, the exact size of the bench.
I read that the bench should be 36" high, so that is the way I built it. Standing on the floor in front of the bench, the effective height is 38" .. uncomfortable for me.