Ron, would you rather have a hybrid which puts on an ear of 16 rows x 40 kernals long with a test weight of 56 lbs?  or a hybrid with an ear of 16 rows x 45 kernals long with a test weight of 50 lbs? 

If my math is correct, the longer ear will give more lbs/acre, even with the lighter test weight.  I think this is (at least partly) what KDD was driving at.  At the end of the day, you are really harvesting lbs/acre - that is what counts.