I'm in a weird spot where Deity is a bit too grindy and hard now for my taste but the last two Immortal games have felt won by Renaissance. Granted, I was in favourable positions (Inca with a mountain start, Arabia with only one direct land neighbour going for a CV) but still.
I think games can have some very big variance on how they go which can sometimes make for some easier/harder games with the same settings. Having good neighbors, and being lucky enough that far away rivals don't get too strong always make a big difference. Last time I had tried Deity though I had felt it was too hard for me and it required me to play in a very strict /objective oriented manner, not very enjoyable.
In this game I'm finishing atm (granted it's just emperor), went conqueror route on my continent, managed to take out 2 civs in ancient+classical (celts and mongolia) and vassal the other 2 that shared the continent (arabia and assyria). I was playing as Rome, so I though the game was as good as won, but I had seen some unknown players losing their capitals in the other continent, though to myself it would be some warmonger who wouldn't be able to keep up with my insane snowballing. Little did I know that I was wrong!
Caravels come around, world council gets founded, and I find, to my horror, that Brazil has the same techs and policies as me (I honestly found the tech part amazing because I had council of elders and managed to spread my religion on my whole continent through conquest+vassalage, so I had tons of free science), and that he had pupetted all of the huns cities except one. China ended up vassaling the huns (and then killing them off during renaissance), and she also had vassaled and crippled england (I think all this happened in early medieval), then during the renaissance when she got chu-ko-nus/muskets she finished england off. Weirdest part of it all, is that the aztecs also were in the continent, and they had also been obliterated both by china and brazil.
I honestly wish I could see a replay of the game with the map uncovered with details on the fights because I'm amazed that brazil and china not only managed to fend off the huns and the aztecs, but then they went and conquered them.
Also, I noted how aggressive the AI got compared to my previous game, I think this was due to me having 4 capitals+mine when the world council was founded, as 2-3 AI declared on me and my vassals not 5 turns after the council was founded and everyone knew who was who.
Have to say, launching an amphibian assault against an enemy who has the same techs and tech paths as you is crazy hard now, I think I spent the whole renaissance+ half the industrial era warring Brazil (killing his boats+bandeirantes) to lower his supply, as any entry into the continent was met with an insane carpet of cavaliers, musketmans and lancers that promptly destroyed anything that landed. So big props to everyone on the team, I found that the AI is getting better every time, and while the production bonuses can be a bit annoying to me this made the game much more exciting and I actually really enjoyed this long war of attrition, going for archeology + freedom to try to keep up my happiness and supply, though I could see how this couldn't be everyones preference when it comes to war.
Can't wait for the next beta to see what will be the decision on how to handle happiness, I'm hoping it will change as I've felt a bit pigeonholed into freedom with this version, not that I mind because freedom seems to be very balanced to me, but I miss some good old autocracy.