I really enjoyed it but - as Hexx alludes to - it fell apart a bit in the last couple of episodes, but you get a bit swept up in it so it doesn't matter a huge amount at the time.
Iron Fist was the weakest aspect of the show by far, which didn't surprise me one bit. The sooner they bury that character - or seriously man him up - the better.
And the post-credits bit! Good lord!