I rather enjoyed playing the culture win with lots more cities than usual. This time I don't have to micromanage exactly 9 of each missionary and 9 temples. The cities can build at their own pace; I have more than enough to keep the three legendaries building cathedrals at all times now. (once Wonsan finishes Taj and Pusan finishes the Hermitage.)
I've considered this several times but always said no, but now saying yes: Liberalism into Divine Right. I actually want Spiral Minaret, and Versailles if I can get a second Engineer out of Seoul, which I did.
And I shut down research here after Nationalism. Sankore trickled research on Printing Press for a while, then finished it with one turn of full research later. Traded for Banking, then decided to research Economics. It would cost only 2 turns of commerce at my culture cities - about 80 commerce - and the Free Market trade route would pay back more before the end of the game. (Still in the Taj Golden Age.) Plus it traded for Gunpowder. Except then I realized Mercantilism was the better choice, since I also went Pacifism and foreign trade routes weren't worth anything on this land map. But the Merchant went towards the 2-man Golden Age which made it worthwhile.
Also took Pacifism with FM - already got most of the temples and missionaries built; Org Rel is diluted by the cathedrals with +100% doublers; and Org Rel doesn't help cash rushing anyway.
The Liberalism into Divine Right move turned out to be the right call. Islam was my sixth religion but it was not overkill. With early mature towns feeding Universal Suffrage feeding three golden ages feeding Mausoleum, and all the cathedral doubler resources, and the legendaries not needing to build temples themselves (my other 10 cities did), the legendaries finished their six cathedrals pretty quickly, by 1100 AD.
Now for some more words on culture mechanics.
The speed of a culture win is really the speed to finishing all the cathedrals. Culture cities basically reach a terminal velocity. The top end of culture production does not materially vary game to game. Every city is selected to feed and work 10-15 cottages. Your civilization always births the same first 6-8 Great Artists on the cheap, then the costs start escalating beyond practicality. The legendary cities always build the same mundane culture theater and library and monasteries, and always get at least a couple culture wonders.
Terminal velocity is always circa 1000 culture per turn with surprisingly little variance. Whether you top out at 800 short by a couple religions or 1200 with Sushi really doesn't much matter. 50000/800 = 62 turns, 50000/1200 = 42 turns. The difference between low-end and high-end culture numbers amounts to just 20 turns of finish date!
No, what's important is the speed at which you get up to that 900+ per turn in the first place. And I've finally learned that Universal Suffrage is the single best piece to do that. Legendary cities always work towns so the extra hammers go a long way towards cathedrals. And cash rushing is very valuable. Not so much for rushing cathedrals directly (you lose the benefit of any doubler resource, though can still be worthwhile), but it's a godsend for smoothing out all the missionary and temple building. Especially when you've got a weak city as the lone source of a new religion, often after flip or conquest, or the Islam founder.
So the rest of the game was an easy cruise from there. I did put some micromanagement into building spies and keeping Counterespionage missions active to squelch sabotage of irreplaceable improvements. This did not help because of a crack in the system: seems that the counterespionage wears off at the end of your turn, then the AIs can sabotage crap before you can run counterespionage again. Sullla clearly did not think through sabotage here. By the end of any game, your land will be a ragged mess of shredded resources. I feel sorry for anyone that tried to take this to space. I was mad enough at having lost three or so resources here.
Culture Victory in...
1360 AD. Beautiful.
Exactly the same date on two games in a row. 
Who would've thought a simple pre-improved map would be as strong as having the two most powerful wonders in the game?