Carrell is a definite winner, just like John Toland from years earlier (The Last 100 Days) in championing facts before fiction. In that great Toland classic, the author details - with first person reports - the systematic, murderous rampages of the Soviet soldiers, who, unchecked by their officers, raped and pillaged their way toward Berlin, and the final victory over Germany. It is NOT a pretty picture, and an often painful read.
Another eye opening account I read many moons ago was Khrushchev Remembers, an autobiographical account by the man himself (translated to English from the Russian by Strobe Talbott). Khrushchev, as you may recall ,was one of Stalin's point men on the Eastern Front, but as time went on became less Commissar and more "Protector" of the commanders under his watch than anything else. He faced Hitler's fabled warriors head on throughout much of the war, including the battle of Stalingrad. Though a diehard communist until the end, he admits that if it were not for the plentiful (and initially secret) American "lend-lease" that was flowing through the back door, the Soviet Union may well have collapsed under German assaults. Used to be hard to find (maybe not anymore with all the e commerce), but definitely worth the read.