I think it's a good start, but it looks rather "flat" in lighting overall, like an HDR effect has been applied. The amount of detail is kind of overwhelming, perhaps as a result of that, you don't get a good sense of scale or even what a particular feature is because there is little differentiation.
I think I would try masking the surface shaders you have to break them up a little and provide more variety, as a start.
- Oshyan
