Played around for several hours last night. Pushed past the intro to get into locations where I knew I could push the performance.
Short version: Lots of problems related to settings, startup, HDR, etc. But once you get past all that, and find the sweet spot for your hardware, it actually runs beautifully and looks great.
Long version:
Problems I had to deal with:
-Game starting into a blank, black screen. Alt-tabbing out and back in fixes it.
-HDR being disabled despite the setting being enabled. Toggling some graphics setting fixes it.
-Togging graphics settings sometimes just stops working. The setting is saved, but nothing changes. Restarting the game fixes it.
-Benchmark stops working after one run, just jumps to main menu after that. Restarting the game fixes it.
-Settings sometimes get toggled by themselves when you're changing an entirely different setting.
-Sometimes after toggling settings some illogical stuttering appears and won't go away without restarting the game.
I had decided from to get-go that I was going to achieve a locked 60 fps, no matter the IQ cost. I have the game on XBX so I've already played the game at 30hz, and wanted that smooth experience. Bad news is that a 2080Ti doesn't get even close to handling 4K@60 on Ultra settings. Here's where I ended up, using Vulkan:
-Set resolution to 1440p
-Set the preset slider to Max
-Set everything that says Ultra to High, except leave texture quality to Ultra.
This allowed me to keep a rock solid 60fps in all locations I could find. Even though it's a shame going to 1440p on a 4K TV, it still looks very good. The AA is good enough so it's not jaggy at all, and the loss of detail, while certainly noticeable, isn't bad. All in all, it's by far the best looking game running at 60fps I have ever seen. And it really runs beautifully too, very little asset streaming stutters or any other sort of hitching. With an open world engine like this, that's impressive as hell.
And that's why I don't really agree with the people saying this is a poorly optimized game. Yes, the GPU demands are super super high if you want to play at 4K/60. So high that there's not hardware out there that can do it. But what matters at the end of the day, when all settings are where they are supposed to be, is how the game looks, and how it runs. And like I said, I haven't seen a prettier game at 60fps, and the performance is nearly fault free.
Guess I got lucky with Vulcan as I have no stutters or any other issues.
edit: system:
9900k, 2080Ti OC, 16 DDR4/3200, game on NVME, Win10 latest version