I am finding the series somewhat spellbinding in its plot structure, the tangled web that it's weaving, and the various acting performances. David Tennant (formerly of Doctor Who among other jobs) is doing a masterful job as DI Alec Hardy in this so far, and he really has some acting chops in this series. Olivia Colman, playing DS Ellie Miller, is turning out to be more interesting as a character than I expected, and she's very complex. The plot twists rolled out in the second episode were varied, shed some interesting light on various characters, and really neat.
I'm looking forward to seeing how this series shapes out and then wraps up. I will definitely have to pick this series up on DVD when it comes out in a North American format, as it's really addictive, and I suspect that re-watching the series will show all sorts of other elements and nuances to the episodes that one didn't see the first (couple of) time(s) that one watches the episodes. In many ways, it reminds me of Twin Peaks and Haven, just done better and British.