This certainly gives you a good 30-second burst of knowledge about all branches of communist, from dictators and despots, to communists and conservatives. I didn't learn anything new, but it cemented some things in my head. I read it one go, as one would read a novel, but it's much better suited as a reference book to dip in and out of as you please.
Of course, the inevitable happens with such short snippets of knowledge - it feels slightly unsatisfactory. However, it does suggest some further reading for each idea if you are particularly captivated by any in particular.