The factors for it at least today, "democratic" regimes:
- have better economy/technology/demography level due to different factors
- have more efficient management due to lower level of corruption
- distribute decision making to different levels, what reduces the mistakes from very above like in authoritarian regimes
- have (again, at least now) higher morale, since there is huge propagandize about that they fight "for freedom"
To the disadvantages would be
- Necessity to reach agreements between multiple representatives - today you can see as this disadvantage diminishes due to... maybe some agreements what we do not really know, or general, interaction methods
- Necessity to be bound the law, also diminishes in different ways - by law reforms and in some situation having this strategy - you know, first you do, then put before the fact that it is done.
I avoided some points, what can be true for both authoritarian and "democracy" models, like the cooperation with same regimes, or usage of hired professionals.
What do you think about it?