Do you have the 35mm by any chance, I would like to see a sample shot wide open. The posted image looks pretty good to me.
Unfortunately I don't have 35mm lens, and I don't think that I will... If I would need a wide angle, I wuold simply shoot a few images and stitch them. I saw your other post for comparison vs. Canon. ZD blows it away - by FAR.
As far as soft trees on the forground - that was limied by the depth of field - a simple lens blur. The focus is on the house in the center of the frame. The trees on the forground were MUCH closer to the camera.