Mostly the game looks gorgeous on a 2560x1080 monitor (60fps is butter smooth) but the UI elements, particularly the sniper scope overlay look terrible. All the new games I've played this year had 21:9 support 'out of the box', and I'm really surprised that Fallout 4 doesn't. Please, please tell me that you're adding 21:9 support soon!????
On the whole though, Fallout 4 is mind-blowingly good and I've not come across any serious bugs yet - which is a real achievement with a game that's so incredibly rich, Diamond City is borderline overstimulating, I was just running around in circles like a headless chicken for the first 10 minutes trying to soak it all in!