yes this is very nice. i'm a little on the fence about the balance b/c the reflection point is dead center on the vertical axis but there's this massive black spot on the top that pulls the image focus up... i guess i wish the feather was farther down in the frame to balance out the huge darkness... otherwise it's a good get!
The first thing that I wished when I looked at this was that the image was large so that I could get a better look at all of those fine feather vanes that you seem to have focused on so well.
The aside, I rather like the composition. It has a nice clean feel to it, which I think the black and white feather enhances nicely. I will admit that the bright spot in the background is distracting to me. It draws my eye, when I'd rather be looking at the feather. If you had angled your shot more downwards, I think the glare would have either been out of the shot or above the feather in a way that would make the scene more ethereal.
You might also consider generating a black and white version of this picture, which may also help negate the bright background and the difference between the edge of the mirror and the darkened portions of the background.
When I first saw the thumb for this I thought it was one of thoes wind-up weasel toys, what with the stripes and all. But great job creating a nice, clean shot! From what I've seen, at least, high-quality mirror shots are hard to come by.