If you haven't read my previous thread, I recently purchased another Sony A7 II for a very good price. I compared it to my older Sony A7 II which is an earlier production run of the camera. After shooting both side-by-side, I noticed the shutter mechanism on the newer A7 II has a sharper sound to the shutter, while the older one has more of a loud thud. I'm guessing Sony made some tweaks with the shutter later in production or some other changes, but there is an audible difference. I don't know if it's been documented or if Sony makes production changes public, but I wanted to make note for those who might be interested!