Sullla:
Then let's consider hills. You have two options with hill tiles, mine or trading post. Mines take the tile from 0/2/0 to 0/3/0, which is useful in a city specifically set up for production but otherwise not really very good. Instead, trading posts will turn hill tiles into 0/2/2 tiles, which the raw numbers rather strongly suggest is superior. And you have the same issue with Golden Ages again: which is better, a 0/4/0 tile or a 0/3/3 tile? Yeah, I know which one I would prefer. Forests are about the only tile where one can make a case for lumbermilling instead of adding trade posts, and in those cases you should probably go with whatever the city needs more, production or gold. Still, in the overwhelming majority of cases, trading posts are the best tile improvement to have. Trading posts are actually BETTER than the bonus resources; I would happily get rid of those stupid sheep on the hill so that I could build a trading post there instead. This is one of the biggest faults of Civ5: the resources have such low yields they become all but irrelevant, and the basic terrain itself is all that matters. It doesn't help either that grassland hill = plains hill = tundra hill = desert hill, and ditto for every forest tile, and grassland = floodplains without distinction between the two. There is a feeling of... sameness about the terrain in Civ5, where everything just sort of runs together. In Civ4, it *MATTERS* where you place your cities, what the terrain looks like, and what resources cities have in their radius. I don't get that same feeling at all with Civ5, which isn't a good thing.