As an instinctive shooter, you will probably adjust pretty easily to instinctive gap shooting, which means that you put the point of the arrow wherever you think it should be to make the shot. For me, this is as accurate as real gap shooting at unknown distances. My experience has shown me that if I pick a spot above or below the target to place the arrow point based on intuition, my arrow is more likely to hit the target than if I guess the distance and place the arrow point on a predetermined gap for that distance. If a person were much better than I am at estimating distances, he might prefer real gap to instinctive gap shooting.
Another problem I get into if I try to use real gap is setting the gap. Let's say I guess the distance is 40 yards, and my gap for 40 yards is -6". So I have to pick a spot 6" below the spot I want to hit and place my arrow point there. All too often, that means my focus will shift to the arrow point and I have to try to remember to shift it back to the target before I release the arrow. If I don't remember to do that, I'll miss high. When I'm using instinctive gap, my focus generally stays on the target, because everything is done unconsciously: I just hold on the target and release when the sight picture feels right.