Thanks for the comments guys, after doing some measuring, mirrow work, and anatomy review... I have gained some insight.
And it is right along with what mr. BobW says
by lowering your anchor point it allows for a more efficient use of muscles used. This means a longer draw with less energy/contraction of muscles used.
I just gained one inch in draw length by switching... that just added alot more force to my arrow with very little work. I may expirement more and see if i can squeeze out another somehow... but i'm not that tall or long of a guy and 28" is pretty good for me.
BTW optimal draw length would come from drawing the hand across the chest, but this would be an almost impractical position, so from there on its all based on comfort which means no one anchor is better than the other... just wanted to make that clear