I'm a southpaw, so I flipped the thumbstud on my benchmade 670 apparition. The screw on the backside of the thumbstud doesn't go flush with the blade like it does in the default position. Also, the clip is not reversable. However, the knife is easily opened left-handed with the thumbstud reversed.
I've got the action and torsion bar adjusted just right so that it opens very smoothly and with great ease. For those who may find the action of their 670 a little gritty or difficult, I encourage you to make fine adjustments on the insertion of the torsion bar. You should be able to get the action to work very smoothly, and the knife should really pop effortlessly. If the action is gritty, either the torsion bar is inserted slightly too far in, or not quite far enough. The gitty action is a result of how the surface of the torsion bar rubs on the back of the blade of the knife. If the angle between the surfaces is not right, the result is gritty, jerky action. After being tightened down correctly, there should be no further need for adjustment.
I've got the action and torsion bar adjusted just right so that it opens very smoothly and with great ease. For those who may find the action of their 670 a little gritty or difficult, I encourage you to make fine adjustments on the insertion of the torsion bar. You should be able to get the action to work very smoothly, and the knife should really pop effortlessly. If the action is gritty, either the torsion bar is inserted slightly too far in, or not quite far enough. The gitty action is a result of how the surface of the torsion bar rubs on the back of the blade of the knife. If the angle between the surfaces is not right, the result is gritty, jerky action. After being tightened down correctly, there should be no further need for adjustment.