Overhand, slingshot and slide release all have their places.
A wise shooter will know how to do all three. Pick the one that works best for you, but know how to do the others as well.
"The Marines I have seen around the world have, the cleanest bodies, the filthiest minds, the highest morale, and the lowest morals of any group of animals I have ever seen. Thank God for the United States Marine Corps. Eleanor Roosevelt, 1945"