I enjoyed it, although the ending was a bit frustrating. I thought that it held its momentum far better than many of the dramas I've watched recently.
I think there should have been more clues to the outcome before the end (or maybe there were, but they were just too subtle for me?). In an episodic drama it's easy to forget little hints between episodes, so they need to be a bit more obvious than in a film or book, and without them we aren't carried along as easily.
Overall I'd give it 8/10 though - it was better than most of the Spring schedule so far, I think.