I know how they work and fit on the gun but I also know that a pistol grip is a poor hilt for a knife and a blade in front of the muzzle is a lever for the bad guy to push the muzzle away from him. Anytime you add hardware to a gun you add weight, ruin the balance and make something else that can go wrong. More better would be a flash light with lots of lumens and some solid weight. That or a shotgun is what floats my boat.
Good intentions will always be pleaded for any assumption of power. The Constitution was made to guard the people against the dangers of good intentions. There are men in all ages who mean to govern will, but they mean to govern. They promise to be good masters, but they mean to be masters.