I think it's worth the dollars. It isn't perfect and it's got a lot to come yet, but they are constantly working on it and patching things. Just make sure you buy it from Ozgameshop, where you can pick it up for half the price it is on Steam - sure you have to wait for delivery, but it's much better than paying 100% more.
The global happiness system is a pretty big hamstring, I will admit. In practice you need every city founded near a resource that you don't already have, or hope like hell the AI will be reasonable, although through patching it seems to have become less reasonable in its trades. I also can't seem to grow decent size cities easily because of it and production is found wanting until you hit steam power and railroad and can get the +100% production from a factory plus a railroad. At first I felt this was rather overpowered, but you pretty quickly realise that it is necessary. Suffice to say the absence of workshops is sorely noticed and every city is going to be surrounded by trade posts and working unproductive tiles. I've not played them, but the Inca get terrace farms, making it viable to work hills [they are +2 production now for all hill types and none produce food]. But when you look at how good some civs get it, this is probably not enough [China for example, the papermaker is a hybrid library and mint for every city] - plus they are DLC.
I'm looking forward to what they have in store though, the game does have plenty of potential, but it does need a lot of work too. That said, I've clocked over 120hours, so for $43, I'm happy.
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