As others have said, there's really too many factors to consider. When I hunt locally, I'm always in a 15' stand. The wind is always in my face (in SW Ohio the wind rarely ever blows from anywhere but the West) and that's all the higher I need to get to be able to see over the rolling hills. When I travel to Central/Eastern OH to gun hunt, I'm getting into the foothills of the App. Mountains and I usually use a climber and get to about 40' up. Even at that height, a deer 40 yards up the hill from me is looking down on me due to the extreme slope of the hills.

The biggest thing to consider is where you're comfortable, both tactically and for safety purposes. If it's always in the back of your mind that you're so low that any deer within a mile will smell you, or that you're so high you'll be skylined, that ain't good. On the flip side, if you're so high that you're afraid to move, you'll make more noise than a diesel engine trying to adjust for a shot.