eric, the wonderful thing is that you "are able" to back off. We who don't have that lens have no hope of getting the excellence that you are getting, and with your standards of excellence, technically, that is the exact lens that you should have, and that all of us would love to have. So the tail feathers are out of focus somewhat, that creates a greater center of interest on the face, where the lens really shines in sharpness...not to mention the background.
Think about it this way...an atomic weapon cannot shoot feathers off of a hummingbird without hurting it. You have an atomic weapon (in a nice way) with that lens. You can do what we cannot do, we cannot do what you can do. Nice purchase!