First impressions: Go watch it now!
Second impressions: Well, i've only watched the first episode and i'm certainly not gonna spoil anything but that first half hour is jam-packed full of worldbuilding and crikey, its engaging. Practically every other sentence just opens up a can of worms I need to learn more about right now...technological, sociological, biological, politicological!
Gonna nip out for some popcorn but I do believe when I come back and put on ep2, i shall be on a netflix-binge tonight!
UPDATE: Finished 5 episodes. Whilst there was some wavering with the usual tropes around ep2 and 3, it really brought the A-game for 4 and 5. This is epic, fascinating stuff.