Read them all, James. Leggett's book especially is a devastating revelation and critique of the Cheka. A virtual must-read for those interested in the immediate post-Revolution period, and especially for anti-communists. As one of the latter, I can't say I was surprised by some of the revelations of Cheka practices and membership, but still... The Cheka truly did attract some of the most sadistic and often psychopathic specimens of the radical left. Even Chekists themselves not infrequently feared and loathed many of their number.
And if photos reveal the soul or character of their subjects (or lack thereof) a lot of these Chekists were the lowest of the low, truly brutish , grotesque. Looking at some of the photos in Leggett, one can almost feel the terror they inspired.
It's really saying something when Iron Felix (Dzerzhinsky) is among the more principled , humane , members of your organization. Remarkable, but true.
Well written book, too, bye the bye.