Just bought a copy and was AMAZED at how detailed and intense it is to watch! As contrived as it sounds but the footage is just breath taking and leaves you speechless.
I whole heartedly recommend this BluRay for anyone with a half decent set up.
On a similar note, i watched the natural world program on BBC2 last night (21:00) and, although only in SD, the image quality was outstanding. Going to have to re-watch this on BBC I Player HD.