I'm willing to bet that very few people are actually hunting at local densities less than 20 dpsm
It's pretty sad that at this point in the discussion that you don't even realize the 20 DPSM we are talking about is the OWDD, not the PS DD!!
Furthermore the harvest rate in 2G does not reflect a PS herd anywhere close to 20 PS DPSM. In 2005 2G only had 12 PS DPSM and the 2008 harvest reflects a similar PS DD.