For us Scandinavians there is a lot of familiar faces in the cast. They really brought the big guns for this one. Casting is great, acting is superb and we all in all get the same from this series as we got from Max Manus, maybe even more.
It's based upon what actually happened, with some artistic freedoms of course. But largely sticks to the story.
If you can somewhat understand Norwegian or enjoy foreign cinema/tv series (not in english), you should definitely give this a try.