If the image needs sharpening, I use a high pass filter on a separate layer, and change the layer blend to overlay, then reduce the opacity as required, Sometimes, it needs the saturation dropping a touch too. If that brings in a touch of noise, then a quick touch of NR cures that.
For web, I reduce the image size to 1024pix, and that will soften it up, so I run a smidge of unsharp mask for that before posting.
But yes, the lens is pretty sharp up to f/11 before a hint of diffraction starts.
Thanks Paul, I've been doing most of my PP in Lightroom 5, I guess I should dust off my copy of CS5 and try to remember how to use it.