That the guaranteed DRT shot... well, not guarantees. I've a pal who swears all his deer have dropped immediately after getting a 270, says it kills like lightning. I like the sound of that - I like the .270 - but since he used to shoot a 30-06 w/150gr JSP, I don't believe we can chalk it up to the cartridge.
I usually go for shoulder. Actually... if angling toward me, I shoot at the front of the facing shoulder. If angling away, I aim through body at the off shoulder (best bet).
No guarantees. I shot one 6pt through neck last year; bang-flop, I might start aiming for neck. An 8pt behind shoulders through lungs, ran about 40 steps or so. And last season I did my first-ever head shot, on a nine-pointer. I'd grunted to get him to stop, and he stopped and looked at me just as he entered thick stuff, all I could see was face and antlers... and at about sixty yards, I shot him between the eyes (I was in a tree, with a very steady sight sight picture). It worked like a charm. No exit; bullet needed up somewhere in the neck, I guess (150gr 30-30)