From what I can tell (and I don't know very much), you can hit the ball well from mid-body hands, "impact hands," a square setup, an open setup, a closed setup etc. Depends on your swing and whatever allows you to perform the imperatives.
I've tested several for me and I'm best with mid-body hands, and a square to open setup. This is because I have a tendency to take the club away inside and swing under the plane. One I do that, I "hoist" through impact. "Impact hands" and/or a closed stance accentuate those faults. PLEASE NOTE- this is just for my swing.
