Spent a few hours playing the S.E today. Can run either 4K Ultra settings with FPS capped at 30, or 4K High settings capped at 60. I use an Xbox controller so even 30fps feels really good. Changed FOV to 100 and DOF slider at 0.
Very smooth. No stuttering, no hitching, no texture pop-in's or glitching. Lighting, shadows and color's look great. Unfortunately textures look crap, especially up close. Hopefully some texture/mesh improvement mod's release soon.