Can't sleep and Unity is out so lemme tell you about my experience so far. I only got access to code yesterday so I'm not that far in but there's a promised Day 1 patch that by the looks of it is SORELY needed. Getting that game to run on max settings is a nightmare, it's a huge resource hog. My 2 980s barely keep up. In the small tutorial area I was looking at some nasty drops one 1 980, prior to Nvidia putting in an SLI profile.
As it stands I can JUST keep it at 60, though it has some drops below at times. The game doesn't really look like it justifies that. It has some killer popin, just like Watchdogs did, actors very obviously and inconspicuously switch between detail levels depending on your distance to them and often just appear out of nowhere and disappear at random.
Lighting is glitchy as hell and overall texture quality is poor. I will say the faces and mo-cap quality is excellent, it actually has a kiss that doesn't look like 2 robots rubbing their faces together, so there's that. The problem that I had yesterday was just the MASS of bugs. Guards spawning in from the sky, NPC actors wandering through terrain and clipping through objects, scripted sequences breaking at random and stealth seems like it's just busted.
I had a guy spot me in a stealth section, run up to me as I was standing and then "lose track" of me. I was right in front of his face, he just wandered off. Thus far the game seems like quite the step backwards. Combat feels much more sluggish than Black Flag, but I admit I have yet to unlock a lot of the weapons and gadgets, I'm not that far in. So I don't have much to say about the gameplay up to this point (its been super standard Asscreed stuff) but this Day 1 patch is sorely needed, because the game without it is a buggy mess.