My brother owns the progressive scan quality DVD of this set and watching it on my component cabled DVD player it was astounding on my 42" LG LCD 1080p. I loved it so much I thought "I need to have this!", but decided why get it in DVD format when I can one up it and go for the blu-ray. I even bought a blu-ray player and HDMI cable just in preparation for this set.
WOW it looks incredible!...until you get to a lower light shot. Something has happened in the transfer to the blu-ray and added SEVERE amounts of dark dark blue (sometimes grey) grain to low light shots. Now I realize not "all" the camera work is done in HD, which is fine, but these scenes looks WORSE on blu-ray than on DVD, how does that happen? The caves episode shows it the worst, some scenes have literal snow on them like partially opaque white noise, and some scenes LITERALLY look like one of those 10yr old VHS tapes with a show recorded from TV look to them. I mean it is absolutely undeniable how horrid some of it looks.
There's forums all over the net complaining about this from up to 2 yrs ago it seems. No idea if it's just -some- of the blu-rays or all of them, not sure if the BBC will recall it or what. But I am truly sad that the DVD version overall looks better than the blu-ray. Nothing worse than sitting down to pure eye-candy (and educational to boot) and switching scenes and thinking "wow am I watching this on UHF?".
For those thinking it may be my setup it's not, I'm watching this on an LG50 42" 1080p using a Sharp Aquous Blu-ray player with the most up-to-date firmware tranferring on a 4' HDMI gold cable. Every blu-ray I have is fine, save for this one.