Eric,
I love the dramatic light you captured here! Great example of a well done low key image (IMO).
The sharpness is good, I like the head angle. You are correct that is awesome light.
IMO the subject needs to be higher in the frame. I like "headroom" but I just feel that there is to much negative or empty space above this beautiful Eagle's head.
If this is not a crop, I would like to see some of the image cropped from the top. And then some from the left to offer balance.
I agree with the crop, however, I would still keep the original, for that would make for an outstanding shot for the cover of a magazine (copy space at the top!).