I use that one when I have fall out under my eyes (pigments, darker eyeshadows, and glitter eyeshadows mostly). It applies enough pressure to brush it off, but it doesn't smear it all over my face. I don't use it all that often, but when I need it, I'm glad I have it. Because of the way the bristles are, the brush doesn't let you apply a lot of pressure.
I haven't tried this, since I just thought of it
It might be good for highlighting cheekbones with highligher dust/pigment, or anything that needs to be applied with the lightest touch.