Having experienced cockpit video in the simulator where it was used briefly as a training aid to review emergency handling (before it was never used again), it's important to understand it is so useless. Viewed from the back looking down at the pilots, you can see hardly anything effective. It's very dark at night. I am not having one of those things looking into my face- it will end up with a bit of paper blocking it!. A very expensive solution to a problem that is not really there! At the end of the day, it does not 'prevent' anything, it is merely a possible tool in accident investigation. All that bother and expense to not actually achieve anything?