
I play on deity and I never use it. I start on Despotism, go for Monarchy at the earliest opportunity, as I think everyone does. Then I will try to get Statue of Liberty and go for an early Communism. When I have upped my shield production to a suitable level (most cities having factories), I change to Democracy (hopefully with Michaelangelos to help control unhappiness).
I have experimented with Republic of course, but found that it caused serious unhappiness problems with no particular benefit, particularly when it's still quite early in the game.
Am I missing something?