As entertainment probably not all that exciting. As a piece of 'historical research' in action - excellent stuff. I intend to watch it again ... and to spend some time looking at the photos (although I usually need them to be interpreted for me).
Some quite incredible research before they even left port (e.g. the time / perseverance it must have taken David Mearns to go through Detmer's account of the battle by following the pencil hole code in that book ...).
And from what was said in the documentary, the seabed evidence seems to support the German account of the battle - although some conspiracy theorists probably won't agree.
As has been mentioned previously, the bow coming off the Sydney probably meant that it sank quickly (similar to the Hood?) resulting in (almost) no-one being able to get off - certainly none successfully.
And now we know why Mearns was so excited about "2 4 6 8" - it meant the depth was in range of their cameras!
If people haven't seen it, there is a 'mass' of information on the ABC site about the search:
http://www.abc.net.au/tv/hmassydney/
layman