I watched this, and enjoyed it, but was later surprised to learn that Herzog had started with a completed documentary but made major changes to the narrative---for the worse! There are few scenes that he edited to tell a different story than they did in the original, seemingly with minimal concern for truth. It really hurt my image of Herzog.

So I'd second the recommendation, but add that if you get a chance, you should try to view Vasyukov's original as well. Herzog's version might be a bit snappier, but I don't think it's actually better. The original is available in four parts on Youtube. Here's part one: https://www.youtube.com/watch?v=fbhPIK-oBvA