I like the fact that more of these 'limited series' are cropping up these days. Too often networks comission too many seasons of something and drag a story out for too long, but it's nice to know you're watching something that has been written as a single story with a proper beginning, middle and end.
I like American Horror Story for the same reason, each story is a self contained thing. In AHS they usually have all the big climactic fuss in the second-to-last episode as well, so there's time to wrap up the story properly.