I'm not a fan of tasers or any form of non-lethal force. If a cop knows it's not going to kill you, and thus he won't get in trouble, he won't hesitate to use weapons against you even if they are completely unnecessary. At least a lethal weapon makes the motherfucker think twice about his actions.
The only time weapons should ever be necessary is if the person is being threatening, and in that case if you threaten a cops life be prepared to put yours at risk. If someone is just resisting, wrestle the motherfucker. Don't tase people bro.