Downies are popular visitors to my suet feeders, and I always enjoy images of them.
A good head angle, pleasant background.
My major concern centers around the light and sharpness. The eye isn't as sharp as the torso and part of the tree. Might be worthwhile to check your focus point. Another round of selective USM on the eye and head might perk it up.
The bird is partly shaded by the tree, so I would be tempted to run a bit of shadow protection to perk up the torso a bit.
Bruce, I think the green in the BG really makes this image special-I think you did well w/ the exposure considering the mixed lighting-maybe a round of sharpening as suggested by Randy. Very adorable!
I am with Randy here. Nice diagonal comp though, but that lack of apparent sharpness in a critical area lets it down a little. Some extra PP work will boost this for you! :)