What Darvin said. I really don't care about the graphics, only if they are immediately connected to the feeling of a siege battle. For example, a siege battle should rage on the walls, inside the towers, in front of the walls, in the city - simply everywhere. It should look chaotic and require proper preparation. Not as in BFME for example, where it was more like "bunch of units walking into other bunch of units in the middle of a camp slowly draining each other's health bars"...
I say: wait till you see the gameplay.
Edit: PS: The DoF screen does not even show a siege battle..