Bests & Worsts Reviews from Amazon

Absolute garbage. I tested it in several spots inside of my house and workshop (thank god I am doing some remodeling anyway) but this thing is not accurate at ALL. You are better off knocking on the wall and making an educated guess. Out of 15 or so attempts on 3 different wall thicknesses not even ONCE did it accurately mark the edge of a stud. NOT ONCE. It just beeps for no seemingly no reason. Is everyone experiencing this? Do I have a faulty unit? There is no way that all of them work at this capacity or Craftsman would not be able to sell it.