If it was the last day of the hunt and I had a 150 class buck standing in front of me at 20 yards broadside,he would definately be going down.A 150 class buck is big in anyones book,takes alot of bone to add up to those inches.
The big 20 point would hopefully make it into another season,and hopefully passed along some of his genes.
The 20 point would walk because I personally wouldent take a shot I am not comfortable of taking,no guarantees,and would be afraid of wounding,let alone loosing such a magnificant animal.