I also have seen tie wraps with the 1 hole in it so that all you do is tek screw and tie tight. I think it is a quicker way to install. I used to use the metal BX 1 hole straps to mount BX also. That was another way to do it. I have also seen where EC's use every trick in the book to try and save every cent that they can on a job. Especially right now when the bidding is so tight. My old boss would make me drill 2 holes in a metal old work box, then cut it in next to a stud. This way he could save the use of 1 madison bar holder. (The metal strip which looks like an "F" that holds old work boxes in the sheet rock.)