It's been a while, but I've finally gotten back to working on this one. This is what I had when I got distracted by Mennin's Hallow:
Click image for larger version. 

Name:	Ascension005-copy.png 
Views:	139 
Size:	108.5 KB 
ID:	5355

I imported a low-res copy of that image into City Designer Pro and started in on it:

Click image for larger version. 

Name:	Ascension006.png 
Views:	282 
Size:	399.3 KB 
ID:	5356

Once I had a layout that pleased me, I brought it back to Photoshop:

Click image for larger version. 

Name:	Ascension008.png 
Views:	211 
Size:	532.7 KB 
ID:	5357

I need to go back and match the resolution of the CC3 output to my original Photoshop image so I can recomposite it properly (the scale sketch is particularly odious).

I still haven't quite arrived at a good way to render the cliff. Any other suggestions or comments? Questions?