When to manually add keyframes vs. letting AE do it?

Turning on the stop watch will add a keyframe then moving the timeline indicator and moving or changing the value would add another keyframe automatically. Let’s say you want something to change position and stay in one place for a while. You could turn on the stop watch to add a key frame, move the item to where you would like it to pause (AE creates a keyframe), move the timeline again to where you would like it to start moving again, press the solid diamond to create a keyframe then move the item to the next position to where you would like it to move to after the pause (AE creates the keyframe.) I hope that this makes sense and is helpful.