For me, this show really drives home what's wrong with network tv dramas as opposed to cable tv dramas. On the networks, they would have had to cram the show with filler episodes. At least one useless, filler episode for every one that actually advanced the plot or established character. But on cable, you can keep the story nice and taut, just twelve or thirteen essential chapters. I reckon the networks do it because they need to stretch out shows so that the can sell bigger chunks of advertising time. But that model has to change someday.
I also think it's the best medium (by far) for adapting novels. A two hour motion picture can't do a novel justice and if you stretched it out to 22 network episodes, you're bound to lose story and pacing. But a nice twelve episode cable series can do it perfectly.
I suspect the right people could even do justice to Alan Moore's "Watchmen" comics, although that would probably take more than twelve episodes.