I like the elegant composition and the beautiful colours. I don't know how close you were so I am probably going to suggest something impractical. I think you needed a little more DOF, or perhaps the bird looking slightly more to the right of the screen then the bill would have been sharper. Also though not terribly critical I would have liked to have seen the tail and wing tips sharper. Having said that I think this is a striking image.
I don't mind the OOF bill at all. It is sharp where it needs to be and the head/eyes and the body. It would take at least a couple more f-stops to have the bill sharp and the tail. Probably not feasible looking at the amount of light there. I'm off to Ecuador in November to photograph hummers so this shot has peaked my interest even more.
This image has so much potential, Stuart. Can you give it a little more space all around? I think it would bring it to another level. Love how the vegetation curves into the image.