I've read a lot of posts that say something like: "I have to set my (insert lens here) to +9 MA, so I'm sending it in for calibration."
I don't own a camera with MA, but this seems strange to me. If you can MA a lens so it focuses accurately, what's the point of sending it in for calibration? MA is there so you don't have to get the lenses fine tuned for AF at the service center, and more importantly so you can fine tune them to your particular body. Right? Like I said, I don't own a MA body, so I'm speaking outside my own experience.