It's the PLUS version of the 104 that was better for the female vocal as it has more bass and fills out the bottom end - though lots of male singers love the PLUS version as well.
The choice of cardioid or super-cardioid often is dependent on if you use stage monitors and where you place them. If the monitor as at your feet, then the super-cardioid would normally be better as the least sensitive part of the mic. is pointing at the monitor. If the monitor is further away in front of you, than the cardioid would be better as the back of the mic. would be pointing at the monitor and the back of a cardioid is the least sensitive bit.
But your friend was correct in saying that the cardioid is more forgiving to head movements that the super-cardioid.