Originally Posted by CAJUNLAWYER

Well I have a 1.0 M&P 9 with the amphibious safety and it goes click when I engage it and goes click when I disengage it. Pretty solid in either direction. You have to actually try to move it from one to the other. Has never engaged by itself or disengaged by itself and from what I feel, it has to be something more than an accidental brush to move it either way. Don't have a scale to actually measure how much pressure it takes to disengage but it feels about the same, if not a bit lighter than the pressure needed to fire the gun using the trigger. And I've got the original factory trigger-no after market parts