Normal feels like I am controlling the vision frustum (where I want to look at), and inverted feels like I am moving the camera itself, as if it was a physical object. I can play both but I definitely have to remind myself what I am trying to control when making the switch.
I vastly prefer non-inverted, because I like the idea of just pointing where I want to look at. I hope it makes sense. All of this apply mostly for games with orbit camera.