What are the advantages and disadvantages of totalitarism?
One should first note that the disadvantages of totalitarianism far outweigh any advantages. Any gains are achieved at far too dear a price. It might also be argued that the advantages of totalitarianism are transient at best.
One of the perceived advantages of totalitarianism is that societal changes can be accomplished quickly. Economic development which normally take a long time can be accomplished with rapid speed. Mussolini's claim to fame in Italy was that "he made the trains run on time." Hitler was responsible for construction of the German Autobahn, and the "people's car" (Volkswagen.) Similarly, Stalin's first Five Year Plan literally forced the Soviet Union out of the Great Depression.
However, as noted above, the price for these gains is quite dear. Totalitarian regimes often silence critics; therefore the free exchange of ideas is conspicuous by its absence. There is little or no freedom of choice; and oftentimes economic decisions bring disastrous results. Stalin's Five Year Plan did bring the Soviet Union out of the depression, but the cost was thousands of lives lost to starvation. A simliar situation now exists in North Korea which boasts the largest army in the world, yet whose people die daily from lack of food. The horrors visited on Germany by Hitler go without saying.