As I understand it, shooting in ProTune mode on a GoPro camera should provide video that has less contrast, producing what looks like a dull, uninteresting image, that actually has more digital information in both the lightest and darkest areas... that can be manipulated in editing, making it possible to lighten darks, darken lights, and pull more detail out of both areas.
I came across a page that provides the author's opinions on the best ways to set up ProTune, and I've set my GP4 up following these suggestions. I'm using Auto white balance for now. Later I want to compare it to Native. It will be fun experimenting!
http://gopro.com/support/articles/advanced-protune-controls-explained