RPG Codex writes: "Storm of Zehir is the second expansion to Obsidian Entertainment's Neverwinter Nights 2. The first add-on – Mask of the Betrayer – was highly acclaimed among computer RPG fans because of its success in the story department and frequently compared to the classic that is Planescape: Torment. When Obsidian announced their new release, many of MotB's fans were enthusiastically hoping for another epic, grim, story-driven RPG. However, it was stated many times by the developers that Storm of Zehir will be vastly different from the second expansion, since it is more in the vein of combat and dungeon oriented games like Icewind Dale.
Well then, I'm afraid I must disappoint those who were hoping for SoZ to be Mask of the Betrayer 2. In fact, if that's the only thing that interests you – no, this is not MotB, you may stop reading, turn around and walk away, because the expansions are to themselves what apples are to oranges. But that's not saying that SoZ is a bad game – quite the contrary, even."