Nerys Ghemor and Thor Damar, I too am a fan of the Cardassians. DS9 deserves tremendous credit making them more than a Hostile of the week. You can imagine a Cardassian as a housewife, doctor, working stiff, journalist or even a bum.
Cardassian society has much to recommend it with emphasis on close family ties and veneration of the elderly. Free market? Capitalist? Who knows? It would probably be closest to the Japanese form of capitalism know as kieritsu. Representative republic? Again, more an orderly clan council than geographic representatives.
It would be good if the Star Trekverse had a powerful and positive non Federation rival/trading partner. The Cardassians and even Bajorans would fit this bill. Every power in ST, except the Feds, seem to be dictatorships or unassimillable feuding clans like the Klingons.
Of course Eddington, the Maquis rebel, put it best that the Federation was like the Borg by assimillating all who joined it. Imagine how dull the Klingons or Romulans would really be if they joined the Federation.