I have watched the first 2 series only as a download, here in Australia, this programme is only shown on satellite TV so is hard to come by, so from going from watching it on my 19" computer monitor in SD to watching it on my 50" full hiDef Plasma is a revelation, the picture is awesome (other than the old footage) everything is in HiDef and pretty amazing to watch. Sadly the sound is only standard Doby Digital, no 5.1 True HD or surround sound here, I think this would have made a great difference.
Some other reviewers say that the episodes search for ET and the Beyond the Big Bang episode are not here, well yes the search for ET isnt here, but the feature length BtBB episode IS ! To be honest I am dissapointed that the search for ET ep is missing, but seeing as I had to order this from the UK, and am not sure whether the uSA version would work on my region2 BluRay player, i will just have to suck it up and do without the missing ep.
As far as the style of the show, well yes it is VERY American, cheesy, sometimes annoying and simplified with basic analogies, it is still watchable, some of the presenters are brilliant, of note Neil DeGrasse Tyson Michio Kaku and the perpetual grinning man. i still find myself going "Oh Wow I never knew that" and am amazed at what an insignificant small speck our planet truly is