Beautiful bird and well-captured. I like the light, details and eye contact. I'm not sure what those spots in the lower half of the BG are, maybe you could blur it a bit.
I'm not familiar with your gear, but with the Canon super telephotos combined with a 2x, you need to stop down to somewhere between f/8 and f/11 to get maximum sharpnesss. I agree with Chris that the feather detail is not quite there. Thanks for posting!
Try using Neat Image on the BG only. In PS3 I usually create a layer that is just the bird. I can then run NR on the Background layer while keeping the bird sharp. You could probably do the same with layer masks.