Life in the Soviet Union's penal battalions was horrific, and this series does a wonderful job of portraying the ugly reality for many persons who perished during the second world war. It is not for the faint-hearted, and certainly extremely realistic when it comes to the ugliness of patriarchal society, and the vision men had (have) of women, many times as mere sex-objects. Certainly the series explores the basal level of the ugliness of human nature, which makes it that much more believable.
Its only detriment, is a cheap politicised usage of religion, especially for Russian nationalistic purposes (otherwise it would have merited a "9 star" rating). Overlook it, and the production is truly a masterpiece of war drama.