Comparison with screenshots captured directly from devkits and the PC version.
TLDR version:
PC: In this comparison, 1920x1080, Ultra settings, 4x Deferred MSAA. Of course it looks better than any console version on these settings
Xbox One:
• 1280x720 upscaled to 1920x1080 with nasty sharpening and contrast filter.
• Whites look about normal, blacks are severely crushed.
• Currently missing AO (devs have said it will be added).
• Textures look similar to the PC version, though detail is hindered by the low screen resolution and the sharpen filter scaling.
• Worse framerate overall than PS4 (singleplayer).
PS4:
• 1600x900 upscaled to 1920x1080 with nasty blurry filter.
• Whites look washed out/dim, blacks are slightly crushed.
• Currently has AO.
• Some textures are misaligned? Textures look blurrier than they should due to the blur filter scaling. Occasional texture streaming issues.
• Better framerate overall than Xbox One (singleplayer).
EDIT: Found a screenshot that illustrates almost all of those points pretty well: