Imo, unrest needs a great deal of fine tuning.

A player shouldn't be penalized by choosing the strategy of building many cities in order to develop his empire.

Granted, a thematic arguement can be made that larger empires do have more management, corruption, and thus unrest issues since the buracracy isn't able to function as efficantly. However, if we move to this approach, than there should be government types to choose from to start with.

In addition, we conquering an enemy city, that city should not immediately impact the unrest of your empire. There should be a gradual change as time progresses and the conquered city adjusts to living under the rule of a new leader. Then and only then should the unrest penalty apply.

During this time of adjustment however, the conquered city should be going through a period of increased unrest, for the very same reason as mentioned above: They are adjusting to new rule.

Lastly, especially on the larger maps, it should not be uncommon for an empire to reach 20 cities without being completely crushed by unrest penalty. Maybe the percent needs to be dynamic dependant on map size?

Anyways, those are some of my thoughts...

That is funny, as a player that prefers small kingdoms, I was thinking that unrest was a complete non-issue and that it should be higher. As it is now, I can just set my taxes to zero and completely ignore it.

Perhaps different government types that fit the individual player's playstyle is the way to go.

I'm pretty happy with the way unrest works. 

I did notice and post that another way to handle unrest if you are of race type = Men (i.e. Altar) is to pump out Henchmen Governors. Even this has costs though (Fame) and is not free.