During the Cold War, comparisons between the state-socialist bloc and democracies sparked scholarly controversy. With scholars pursuing innovative comparisons between China and other political systems, it behooves us to revisit some of the questions that such comparisons pose. Specifically, when is it reasonable to pursue them, what is their purpose, and what do they entail? Giovanni Sartori usefully cautioned against comparing unlike entities, yet his advice was overly confining. Sometimes gaps or disjunctures between political phenomena in dissimilar political systems provide opportunities for innovation, even if they complicate Mill-style comparison. In particular, such projects can provide intellectual payoffs through the way in which they frame a topic of study, specify its universe of cases, and scrutinize the gains and risks of including phenomena from disparate contexts in a common category. Further, they provide opportunities for conceptual development by elaborating on and exploring these shared phenomena. Such cross-regime comparisons are not always feasible or useful. When successful, however, they can provide rich and thought-provoking new theoretical and conceptual departures. I illustrate this with examples from research projects comparing China with the democratic systems of India, Taiwan, France, and the United States.