It is hard to consider how good one of David Attenborough's shows really is, because they are often so filled with amazing natural things, that this is what sticks in the mind. Of course though this show is as strong as ever in terms of the technical delivery, and even with the challenges of shooting, it looks great throughout. Likewise the sense of wonder in the delivery is palatable. Not only do I enjoy the feeling that a man who has lived so long doing this is still amazed by what he sees, on top of this it is that the footage entirely justifies this. The detail of the ecosystems is fascinating and there is plenty of great images which support the interesting narration.
I am not sure why I did not totally love it though. The 'making of' at the end of each episode was not as interesting as it could have been, but I also felt there was not as much great footage as there could have been. It is not that there is a lot of padding, but it does feel like they didn't have to be brutal to fit the footage into the running time. Instead it feels like there was plenty of non-reef material in the main chunk of the show. The submarine, the footage of the briefing, bits like this all took time which could have been instead spent under the water with the reef. The 'making of' highlights the many challenges, but still, I watched every episode loving what I saw, but wishing they had taken more time with it.