I don't think that all societies are in need of such drastic reformation as Plato thinks. I would probably be more interested in Aristotle's idea. Aristotle discovers that the best possible has already been obtained. He says that the society already has everything that it needs. All that can be done is to try to improve the existing society.
Plato's Utopia consists of three class systems. These class systems are distinct and non-hereditary. They are the Guardians, the Auxiliaries and the Workers. The Guardians consist of non ruling Guardians and ruling Guardians. The non-ruling Guardians are a higher level of civil servants, and the ruling Guardians are the society's policy makers. Auxiliaries are soldiers and minor civil servants. Finally the Workers are composed of farmers and unskilled laborers. The Guardians are to be wise and good rulers. It is important that the rulers who emerge be a class of craftsmen who are good with the public, with a good temperament and they should be good in the areas of governing the state. The Guardians are to be placed in a position in which they are absolute rulers. They are supposed to be the selected few who know what is best for society. .
Aristotle disagrees with the idea of one class holding discontinuing political power. He thinks that a state should be governed by a Philosopher-King. He also thinks that the failure to allow circulation between classes excludes those men who may be ambitious, and wise, but are not in the right class of society to hold any type of political power. Aristotle looks upon this ruling class system as an ill-conceived political structure. He is saying that Guardians sacrifice their happiness for power and control. Guardians who lead such a strict life will also think it necessary to impose the same strict lifestyle on the society it governs. This is where he sees the dangers of a society of this kind and why he does not agree with Plato.