Like at Futarchy for an alterative model. (Though you could classify it as democracy.)

The problem, of course, is that what is considered "benevolent" is entirely up to the dictator to decide. That alone makes it a non-ideal government type.

No, it is up to the coherent extrapolated volition[1] of the dictator's people. (At least, it seems like a good guess.) What makes a government less than ideal is its failure to apply that volition. The question then is how hard a given type of governance is likely to fail.

Now I agree that for a host of reasons (like taking one's own volition for the country's CEV), dictatorships do not rank high.

[1]: http://singinst.org/upload/CEV.html

The point of a dictatorship is that the people don't have a say. The dictator does what he wants and portrays himself as benevolent through state-run media.