F80EXR: How good is that lens?

Darned good. Easily as good as my F70EXR from what I can tell. My traditional bush shot, but this is through a window, so I processed it for contrast and sharpening in ACR. Only output sharpening in CS4.

And here is the same image with 100% crops in the corners and center … if this is not good enough for you then I encourage you to remove your head from between your cheeks …

So, the F80EXR has a pretty good lens. Good news there.