I thought the video quality of this BD set was quite bad overall. Especially during landscape zooms or when displaying darker areas (and not only night or cave shots, but like a sand dune in part shadow for instance).
For me, the picture flickered alot during the above mentioned scenes (in the areas affected) which was annoying. Then in other sequences the picture was totally superb overall. Guess the transfer to BD was not that good, or something? I only have a handful of BD:s since before but none of them are lacking in visual quality as "Planet Earth" is.
Note: This series in itself is excellent, so my average rating is mostly due to the lacking visual presentation!
Also, only English subtitles was a let-down for me as well. Thought there would be Swedish subtitles hidden somewhere, but no. I´ve noticed play.com rarely list all available subs on their available items.
Just my two cents.