Here you go, plus some more comparisons since I found the results interesting. The Terrain setting also controls some of the foliage in the world, which you'd normally think is only controlled by the Vegetation setting. Both set to Ultra produce the richest looking foliage and vegetation. Putting one at High and the other at Ultra produces different results.
Tons of pics incoming. All of the screens were taken at max settings except Shadows and Tesselation at High, and MSAA off.
There you have it, make of it what you will. Performance hit is pretty minimal for both settings, like 1-2 fps on my 4GB 770. I would leave both on Ultra, but I haven't tested if setting Terrain to high actually fixes cutscene stuttering.