Mine also. Instead of having to use both the shutter and back focus button most of the time, I only need to hit that button when I want to lock focus.

Steve, who does a great job of explaining things, mentioned that with BBF if you are doing something like landscape you can let go of the camera and not have to refocus/compose when you go back to the camera. I suggested pressing the focus lock button before pressing the shutter. He honestly said he never thought of that. I have read other authors saying that without BBF you need to switch to manual to keep the focused locked. My feeling is they were promoting the trend, or they too never tried using the focus lock button (same button, programmed differently).

I also like keeping my thumb free when shooting wildlife to be able to move the focus point when a subject changes direction. I realize that many just aim for the center and crop later. I try to crop while shooting as that's what I was taught many years ago. Somebody once responded that nobody does this while shooting, but I have to think the joysticks were added for a reason.

In reality BBF or Shutter Release Focus work equally well. My suggestion is pick one or the other, otherwise things could get really confusing.

--