Important info first: Do not take this class if you enjoy history.
Despite being a motivated history major, this class drained my desire to pursue any further study in the field of German history. The material for the class was incredibly dry, although Tooze tried to inject humor into the lectures, it did not change the fact that he did not stop talking for the entire 75-minute lecture. Usually, that's no problem, but the dense content and text heavy slides (usually 50-60 slides per class) made it impossible to keep pace. This is before considering the weekly 100 pages of (obviously) dry reading.
Now, think of the above. Not terrible right? Considering there is only a midterm and final (typical: 12 IDs/pick 6 and 4 essay questions/pick 1), should be cake. Wrong. Tooze will not provide any list of terms that may be on the exams. Leaving you to pore over hundreds of lecture slides, pages of readings, and personal notes to find what he may have considered to be relevant enough to appear on the midterm/final.
That said, most people I knew in the class did well (I got a B+), but I feel like it very much depends on the TA you get. I do not believe it was worth the effort, especially considering the other great class offerings within the Columbia history department.
Side note: Once, during lecture, a student tried to ask a question. This only happened once, as Tooze's response was to shut her down in a very condescending manner. Not sure if this was an isolated incident or he has different behavior during office hours, but it was pretty ridiculous. First and only time I've seen that response from a professor in three years at Columbia.