I've now played most of a game (up to mid-19th Century) with the new patch.
- I was impressed in my first two games with the AI's coordinated attacks on my cities. This was, however, on Pangea maps, and in the early game where the AI is arguably already fairly good at city attacks.
On my current game, which rolled a continents/islands map (not sure which - I always play on Shuffle. Normally continents only has two or three major landmasses, but there are more here, most bigger than I'm used to on island maps) naval warfare is obviously more important - and if anything the AI is worse than I'm used to post-G&K. Civs still have little trouble capturing cities on their own landmass (China took Monaco early, I lost Samarqand - given to me as a peace offering, so without units nearby to defend - and later Hsia on the same island to Ottoman and Polynesian forces already there), but China in particular was truly bizarre.
In several attacks on my continent, with a reasonable mix of naval melee and ranged units, Wu just parked outside my cities ... and then decided to sail round the island being picked off as she went. Land forces did the same after disembarking (which, given that this was in the gunpowder era, did give me a War of Independence feeling as my minutemen partisans sniped passing Chinese units...) Other naval assaults have been small and poorly-supported, as from Elizabeth on Seattle. I've noticed that, while the AI can take other AI cities from the sea, it's generally slow to do so, and some behaviour is very odd. For instance, Elizabeth declared war on Lisbon, parked Ships of the Line outside it, and just kept losing them.
It got worse in the modern era - Sully finally got bombers, but although he also had plenty of ironclads he didn't coordinate them, and so didn't attack with sufficient force to take the city, giving my own bombers time to destroy his forces. And this is the AI that, shortly after the G&K release, launched the most effective modern era combined naval assault I've seen from a Civ AI.
- There seem to be some strange new bugs with diplomacy. A declaration of war now doesn't seem to cancel a DoF if backstabbing is involved (which is happening a lot in this game with my heavy use of defensive pacts), so I've had civs simultaneously described as being friends with and at war with me or other civs, and even get the notification that a DoF has ended and needs renewal while I'm at war with the civ in question.
- There's an annoying new issue with defensive pacts (as well as the pre-existing one that they often seem to cancel before the 10 turn limit is up even if neither civ involved has started or become involved in any new wars). The system seems to let you have multiple DPs at once with the same civ (up to 3 apparently), and they will typically all cancel together. Since there's still no way of tracking the current status of a DP other than clicking the diplo menu and seeing if there's an option to initiate one, this happens quite a lot.
- Some less extreme variant of the scrolling bug appears to have returned.
- There's another returning, in this case minor, bug when attacking cities - you can often see the city's final (post-attack) health when the attack starts, the 'correct' value only being reset when the first attack resolves. This is similar to the longstanding bug with planes that showed their final health as they started their attack run; this actually seemed to have been fixed, but now I'm again seeing the plane's final health before the animation finishes.
Sejong though if he gets close to tech victory 
. I would assume that the main multiplayers on the community don't play with AI, but for those of us on LANs / private games we have AI on all the time if there's space on the map for them.
