Rock surfaces are always fun to do

For this one you may consider either tuning down the AO in the GISD or tone down the overall roughness of your displacing shaders.
There's so much detail in it now that it starts to look quite literally 'incredible'

I generally use AO of 0.5 and then bump up the "bounce to the ounce" to 3 or so.
You probably know this, but the default 24px works nicely for 800px wide default render nodes.
If you render bigger you also need to change the radius along. At the cost of some extra render time, of course.