In my opinion, this image is oversharpened to the point there are artifacts. I would dial back on the clarity slider quite a bit.
Thank you Mat. I will give it a go.
You have way too much sharpening. If too much sharpening is done, the pixels get a halo around them, and the picture looks very 'grainy'.
If you enlarge it you can see what we mean - (maybe not so clear in this small example).