well Nerosrevenge since you asked and I quote....
"Personally I can't really see an advantage to going up beyond 9-12 feet. Even if you consider the deers ability to wind you, would anyone dissagree "
well yes the deer do use there nose and eyes to identify those who wish to kill them...and if your low in a tree you can get busted pretty easy movin around even if your careful, and if the wind is not good to you or if a deer sneaks up behind you they may smell you before you know it..so logic tells me if your higher in the tree your more likely to stay out of sight and the scent will carry further before it descends to the ground...so in some cases yes higher is better..not a given I will say,, and I have harvested deer on the ground...sayin all that I will say sometimes there seems no rhyme or reason..I can do everything wrong,,noisey, stink, bad wind, ect....and low and behold here comes a deer from down wind...
I do get away with more movement at 15-20 feet up.and I try to play the wind always first

.I try to scan the woods well and as long as I get the drop on them i can be ready for about anything...IMHO..
Dedicated.... ta all the sweet Bucks yet ta die!