Hi John,
it will probably be easiest, if you change the Sculpt Mask Overlay from 0.75 to 1.0, then it will be better to see how much effect the Mask has, but the Overlay doesn't change how much effect the Mask has.
The Strength is what determines how strong the Mask Strokes are. A Strength of 0.5 will create a Mask Stroke that has only 50% effect.