If you are going for detail & quality you may want to try these options:
Turn off texture filtering on your materials.
Have your min shading rate on your figures & render settings low, try for between 0.1 - 0.2.
Have your irradiance caching as high as possible.
Increase your pixel samples.

Sorry I can't go into more detail, I've been up for over two days & I'm falling asleep as I'm typing..................................................................................