Intuitively, a state with a dictator should be more chaotic than a democracy, because the decisiveness mentioned in the grandparent comment would result in a loss of coherence in policy, since all the interest groups in the government would not have been brought on board in time. At best, this would lead to miscommunication, at worst, revolt.
I'm not sure that decisiveness is a natural characteristic of dictatorship, though. Most dictators sit at the pinnacle of large networks of clients and rely implicitly on their network of relationships to maintain legitimacy. This would imply they would have to be more 'softly-softly' than an equivalent democracy, because they can't rely on all the systems democracies have to legitimize contentious decisions (elections, etc).
I'm not sure that decisiveness is a natural characteristic of dictatorship, though. Most dictators sit at the pinnacle of large networks of clients and rely implicitly on their network of relationships to maintain legitimacy. This would imply they would have to be more 'softly-softly' than an equivalent democracy, because they can't rely on all the systems democracies have to legitimize contentious decisions (elections, etc).