15 feet will work, 20+ is better in most cases. It's NOT however if you're uncomfortable up there. You'll find that the more you hunt from above the more you're willing to squeeze out a couple more feet and those few feet do help with scent control and movement if you have cover. Sometims the smart thing is to stop lower so you have cover. Each stand is itself. Even with my climber I find that as the year progresses I feel much better going a few feet more. Early in the year heights scare me.