The show was great, the moral/ethical discussions took most of the plot with little space to romance, which I personally don't mind (I started the show keeping in mind that the romance was only a background factor).
If you're as biased as I am about the topics in the show it can be a little bit frustrating, especially towards the end, but it's frustrating in a good way (?) if you get what I mean.
The mistery keeps you watching, even if a little bit predictable, and a few plot wholes and continuity errors weren't big enough to take away the focus from the actual story.
Great show overall but I DEFINITELY need to watch something more lighthearted before even thinking of rewatching this one.