i like the head angle and the light is fantastic!! i see some noise in the shaded area under the wing. looks like you could have lowered your ISO a little without sacrificing enough shutter speed not to get a sharp image. i might would add a little more contrast for a little more punch, too. love the placement in the frame.
I agree with you Brian - I just love those iridescent colors and plumage patterns on the underwing areas. Nice capture of this fast flier, and lovely light. Wish for a slightly better head angle or the bird flying a tad more toward you, but lovely image all the same.