Looks good to me.
The only slight changes I would make concern little bits of out of focus reflection in the distant water area. A small spot under the bird's beak and towards the right side a little vertical spot directly behind that thin reed which slopes diagonally. Simple to clone them out.
Bill, very nice capture, the contrasts in the Heron's plumage are spot on.
Now I see them, (I didn't at first), I think Geoff's suggestions are valid though perversely, I don't find the 'rectangular' halo around the heron's head distracting. The symetry of the beak 'in line' with the water line behind the bird's head, combined with the reflections in the water quite works for me. though I suspect I might just darken the lighter reeds to the right slightly.
Nice image; liked it