The 4th episode about the execution squad was very realistic and emotional. If you haven't watched the HBO show yet, watch it. It has got a
9.7 rating at IMDB right now.
P.S. And as a one who lived in Soviet Union I can confirm that everything is true. Just a single note: we have never used a word "comrade" as often as it shown in that movie. "Comrade" in Soviet Union was something like "mister" in English. How often you say this word to someone? Everything else it absolutely authentic.