I voted stand but like someone said above its 50/50 depending on where I'll be hunting, stands limit you to that exact spot but the ground hunter can drift around in an area or take advantage of no trees or blow downs ect..
I'd also say that both being effective is 50/50 if you have a ground hunter who can sit still and not move then no matter how close the deer will not see him, if his clothes are silent they shouldn't hear the draw also..
many folks cannot sit on the ground because they been busted so many times,,, so with leaving the wind out of this for now as an act of god the 2nd biggest reason is movement and 3rd is sound.
folks in tree stands get busted just as much they just don't realize they where smelled or they get caught turning their heads looking around like they watching a tennis game.
those are my facts anyway based on what I have experienced