This book is full of nuggets of incisive evidence-based scholarship wrapped up in unconvincing feints toward traditional 'totalitarian theory' histories of Stalin. Like they were afraid the book wouldn't get published if they didn't pay lip service to the 'left' anti-communist intellectual crowd, especially in the first handful of papers. This serves to strengthen the positive, evidence-based images of Stalin because those come off as nuanced and alive while the Western traditional received wisdom elements are cartoonish and one-dimensional.
This is a pretty great history book, especially considering it was written by bourgeois historians. Reading it with an understanding of class struggle and the dictatorship of the proletariat will give the Marxist reader many useful and thought-provoking insights, especially if paired with a reading of a book like Another View of Stalin by Martens.