Nick Irving over at The Load Out Room analyzes the increasingly popular “C”-Clamp grip. It comes from the competition world where targets are mostly stationary. However the major draw back is the lack of peripheral vision on your support hand side. There are other issues with using this grip method for defensive use. Exposure to vital organs and discomfort for sustained periods of time. He mentions obstruction of sights, however i have not noticed this on my Troy Carbine. The integrated front sight is tall enough that I do not see my thumb. But if you have a weapon with low sights, like a H&K UMP, then the thumb could get in the way.