This is one of those series that you actually have to listen to, not just watch. If you're just watching it, don't be surprised if you get lost and don't understand anything. Multilayered, deep, with lots of philosophy, sociology, ethics, morals...in one word: complex. But that's why it's absolutely loveable. If you like to think, that is. And of course, a central dilemma: the borders of human and machine...
Having finished it...have to say, it's highly rewatchable. Either to better understand those fine details, or to be able to jot down thoughts you might wanna blog about or discuss...because there's a LOT in it, in each episode actually, but you're too caught up with the actual story and the characters the first time. Choice is yours, but you'll definitely start it over again after a while.