With advertising jobs, most of the time I'm locked down on a tripod, shooting to a layout. I would not want the camera body to be in a slightly different place each time that you brought it back after recomposing.
Also, in advertising, you're always planning on Head Swaps, so you want the frame pretty much locked down, frame to frame, so that everything stays in registration.
I cannot imagine, each and every frame, moving the camera body to the focus point, and then bringing it back to recompose. Frame after frame. What would you have to do -- unlock the camera position, go find the focus point, then hold down some button, and then recompose, make sure the horizon is level, and then relock the tripod, and then shoot? Each and every frame?
I guess it's a cool idea, if you're into NASA stuff, but if you're doing ad work, down in the trenches, you want the camera locked down. That's why I'd opt for Canon or Nikon, with multi point AF. Not that that is perfect either, but it's a pretty rare job where the focus point is dead center for me.
I've found that, with these digital cameras, the focus tolerance is next to nothing, and I cannot rely on Manual Focus any longer. The viewfinder is either too small, or what I'm seeing is not exactly what's being conveyed to the sensor. The AF point in the 5dII pretty much nails it every time. I've heard the same is true with Nikon, maybe even better than Canon.
It seems to me that the majority of the MF market share is now headed toward advanced amateurs, which is fine on some level, but a shame on another level.
Mr. Grover, are there plans at all for a Vertical Grip for the H body? For people who don't shoot landscapes and sunsets?