I loved "The Witch" and thought "The Lighthouse" was interesting but flawed. This film is a bit like "The Lighthouse" in that respect, interesting, worth watching, definitely, but it was flawed by a plot that seemed a little bit cliched at times and dialogue that was a bit dull. Also, as much as I liked Skarsgard in "True Blood," he's not a great actor and wasn't very good here.
Nicole Kidman was wonderful, though--she gave the best performance of the film--and Gudrun's version of the story was so interesting, I wished that it had dominated the film much more. The scene in which Kidman's Gudrun reveals her story was the best in the film.
I did also love the scenes depicting the rituals the Bersekers took part in to prepare for battle, the scenes depicting their shamanistic religious beliefs, and the scenes with the Valkyrie. It's not Eggers' best work, but it is definitely worth watching.