With institutional checks and balances in place, the executive, the legislative and the judiciary and other smaller check and balance institutions are expected to independently function to ensure that power is not abused or misused, and every one works towards the betterment of the country and its people. With such a system in place, one essential ingredient for a successful democracy is the creative friction. Difference of opinion is expected and should be fostered and must be dealt with respectfully.
Unfortunately, in the want of a giving an opportunity for the best to rise, the defined period of being in power brings with it the unwanted issue of vested interests and bias. This would not be the case of a assured unlimted tenure in an authoritarian government, however, such unlimited power can be a cause of huge distress in the wrong hands. The examples are of China where, implementation if relatively easier with the 'power of god' vested in them, while in India, because of the higher fairness and stronger voice of democracy, often, even essential and good decisions get delayed in implementation because of the many interests in play. All this being said, I guess the idea is of smaller sacrifices in the name of democracy over a autocratic government which someday might fall into the wrong hands and destroy all that's been built and carefully nurtured.
In my opinion, Democracy has a better chance of fairness and equality in the long run. The essential ingredient would be a good educated mass who recognize the responsibility to their own future. A successful democracy would be in place when the mass are able to vote for the best candidate instead of candidates who are related or are friends.