I really enjoyed this Gazetteer. It has a lot of information on the history and traditions of the Northlands. It is a fantasy version of Scandinavia, so if you are expecting historical accuracy, you will be disappointed. The book includes new rules options, a clan of insane dwarves, and all sorts of challenges for your characters to face.
I took off one star because the book makes no mention of the Immortals Forsetta and Cretia, which are central to the plot line of module X3 (set in Vestland). Also, the book makes frequent references to the nearby nations of Rockhome and Ethangar. Neither of those source books has been released yet.