Good points, North Texan. Spotlight counts might have some validity IF you've got a food source that draws the bulk of the deer nightly, and IF you've got roads that allow you to get beside those food sources. Neither IF applies to my neck o' the woods.
If you have a food source that draws them specifically to that area in bulk, you really can't use it because it distorts the true numbers of deer on the property.
The spotlight survey does have its flaws, but it works pretty good around here. Although, the helicopter survey worked a little better and was probably a little more accurate.