hardrunner. Don't know what to tell you. I'm at a loss. I've owned and shot a number of GN Ghosts. All have been very good shooting, forgiving bows, handling a pretty wide range of spines.
If your arrows are going left and right, it suggests a form problem. Too stiff or too soft and they should be consistent one way or the other.
If you can consistently hit by holding high, then maybe the bow's weight is mismarked. Maybe it's much lower than marked. Not likely, but possible. Does the arrow feel slow to you vis-a-vis your other comparable weight bow? I'm grasping at straws here.
Just for the heck of it, you might check the tiller on your bow. It's unlikely, but the limbs might be out of tiller.
I'm assuming in your comparisons to the ILF bow, you're shooting the same arrows.