This is the best tool for retouching hair to remove stray and fly-away hairs.
Use the darken and lighten modes to protect some pixels, rather than always using normal mode. (Ref 5:25)
It can be used for removing large areas from an image such as whole figures. (Ref 6:50).
The Spot Healing Brush does not have a setting for ‘Current and Below’ (Unlike the Healing Brush, which does), which means that if you are retouching with a Black and White Mask in place (So that you can see tones better) it will look fine while the mask is there, but reveal that the wrong colour has been applied when the mask is removed