It depends upon the range and number of shots required. For a home invasion, I would not want just one dart that comes out of the gun to stun only one assailant. On the street, from my experience, size matters. Tasers are pretty bulky and are not easily concealable. My favorite for every day carry is a mini 1911 in 9mm. Very slim, and easily concealable with even a 10 round magazine.