Hmmm, using my known analogies, it's seems like this:
CivIV is to CivV is like Shogun2 to Rome Total War. Let me explain:
I HATE/LOATHE the HAPPINESS mechanic in Civilization V ... once I'm large enough and by the time I conquer a second civ's capital, my Happiness is -30s, ebbing away slowly, way too slowly. This is the case right now at turn 134 of my Ottoman campaign in the scenario Into the Renaissance. I conquered Cairo of Ayyubids from Saladin (funnily enough Songhai leader lol) about eight turns before and just conquered Constantinople of Byzantium from Theodora. My entire empire is stagnating, even though I can't build anything more in my core cities of Aleppo, Edessa, Acre, Jerusalem. Now the mega-cities of Cairo and Constantinople are added. How the hell do I get out of unhappiness?
It seems that unhappiness is easier to manage in Civilization IV, as one can have more cities. In Civilization V, one is penalized for starting each new city.... personally, imho the most fun aspect in Civilization for me is starting new cities and naming them accordingly/realistically to their map location/historicity.
While Rome Total War was an awesome game, I hated it's SQUALOR mechanic. Basically, by the end of the game, your cities become so large, that they're filthy and much revolts and Rebel (think Barbarian in Civ terms) spawn up everywhere.
Imho, Shogun 2 did a WAY better job at making it possible to appease your populace eventually, not causing your cities to turn too large and cause unhappiness. Shogun 2 also handled expansion much simpler and easier to understand. Build a castle, be prepared to support it with food and extra population. This meant that NOT every single region NEEDS a castle. Actually, it prompts strategic thinking and making sure that castles and large towns are erected in the most strategic locations.
I made the noobie mistake in my first CivV games that I bestowed every ugpradea and building in each city. WRONG way about it, it seems. CivV favors a few, strategically placed LARGE, mega cities and many smaller (pop3 or below) cities supplying it with Luxuries and Entertainment, but not becoming production or military hubs themselves.
Am I starting to understand the mechanics more? Or am I dead wrong?
PS: Is there a way to switch Capital from one city to another? What are the effects of that in Civ5?
I hated how capital placement was crucial for Rome Total War. Too far away and the farther regions constantly rebel. I guess it's realistic, but not realistic in the sense that no matter how many happiness/sanitation buildings I constructed, didn't do squat.