I don't really care either way, but if the video feed is digital (and it most likely is) there MUST be a delay due to the digital compression and decompression of the video feed from the cameras. Given that these are non-essential, entertainment cameras (I assume) the priority would not even be on making this delay as short as possible, so you can be sure there is one. Another delay is added due to the IP network infrastructure feeding the displays around the plane (again, non-essential, entertainment). Switching/routing gear can and will add non-negligible delay. Also, I assume each display is basically its own computer with an operating system and layers of object programming, again, creating little delay. The TFT displays themselves have a relatively big delay (compared to CRT/plasma they are at least 4000x slower). So, from a technical point of view, the delay is there and has to be there. It may not add up to be seconds, but half a sec to a second is totally normal.