Andrew, Birds of prey and owls are my passion and I know how difficult it is to get a shot this good. DOF is fine for the lens that you have and the wing blur is great to show the movement and at 1/640 I'm surprised it's as sharp as it is in the wings.
If I had to say anything negative it that it looks just a tad over sharpened for me.
Great job on a difficult capure.
Cracking shot, beautifully sharp and excellent bokeh