I bought this as one of my first Blu-Ray purchases, hoping to sample the best HD can offer. And in places this set truly does soar, offering jaw-dropping imagery of our extraordinary planet in jaw-dropping HD. But the next moment this beauty is soured by grainy flickering or strange noise in the darker areas of the image. Just as I begin to suspect it's the TV or the player the next image is stunning. Having tested several other Blu-Rays that showed no signs of the issues plaguing these discs, I can only conclude it solely the quality of the transfer that is not up to scratch. This is a great shame because as a series overall, although not up to the lofty standards of the seminal Life on Earth, is a fantastic overview of our planet. The time, care and effort gone to capture not only the familiar images, but footage of places and events possibly seen by only the lucky few can now be appreciated by all. I can appreciate certain footage is going to be grainy due to the varied nature of the photography taken all over the world by a team of talented cameramen, but when what should be a beautiful tracking shot of a pristine lake is marred by unnecessary grainy flickering I find that very disappointing. It is very difficult to fairly rate the series because of these issues. For the series itself I'd give a 4 out of 5. For the best images I'd give a 5 out of 5, for the worst images I'd give a 2 out of 5 and for the slightly poor sound a 3 out of 5. Which is what lead me to my average score of 3 out of 5. If you have a 720p TV you may not notice all of these issues or if you love nature documentaries I would heartily recommend this boxset. If you just want a HD show reel, this is not the one to get.