I've found them useless, with very little information other than what the CVR gives you. All you see are heads moving and arms reaching out. I think I would take great delight in putting a dab of vaseline on the lens. They are intrusive. The trust has already been breached with playing CVR tapes for public titillation. They are not having me on image as well....period.
The promise was these investigative tools were for accident investigation by accident investigators ONLY. They let us down with CVRs. They simply are not going to have the chance with video.