I really like the way the diplomacy works now. One thing I've noticed is how much it depends on the map and settings. With only the standard amount of civs on a continents map, or with a few extra on an archipelago, it is certainly possible to stay friendly with some civs for the whole game. With 20 civs on a pangaea, not so much
But I like being able to tweak the settings depending on what type of diplo game I want.
In a recent game, I was France doing a culture win on an archipelago. Most civs were getting along so well that I decided to liven things up by denouncing the most warlike (and so least popular) civ, Genghis who had been attacking city states. Next turn 2 of my friends did the same. Turn after, more civs joined the 'we hate Genghis' party. Realising for the first time I had
started a denouncement chain was a
moment. The shared denouncements helped keep friendships and even got Gandhi (who didn't like me trying to win by culture) back to friendly status.
My current game, I am Songhai on a 20 civ large pangaea. I have 2 cities of my own and have taken 4 puppets, and at the moment I still have 3 DoF partners and quite a few other civs that are still friendly. I got quite a few opportunistic attacks against me early on, but managed to survive them. Monty came very very close to taking my iron city but none of the others did much.
My favourite moment in this game was joining a war with 2 of my DoF partners against Siam, who had been really really annoying and declared war on me twice before. I took his capital then bombarded his other city down (he only had two because he lost some settlers to barbs early on, then spent all his time building warriors to attack me). I let my pet city state strike the final blow so I wouldn't take a diplo hit for killing him. That's what diplomacy should be like - vicious and sneaky.
Our alliance is crumbling now because Iroquois has started too many wars, my other two friends have turned against him, plus strategically I need to take out Rome and from then on it will be a total free for all. But I should be strong enough by then to handle them.