Yeah, one of the best photos I ever took is of El Cap and really shows the faceted nature of the rock. I think I have the general granite tint/texture right - the 'Gunsight' formation opposite El Cap in the render looks about right. El Cap itself is darker because of the shadow, but it needs a more faceted appearance, and mottled areas of redder/browner/whiter rock.
Manzanita actually grows in a variety of forms. In the foothills it grows as small trees, maybe 20 feet high or so. At higher elevations it grows as an extremely tough ground-hugging shrub. The wood is really strong and has a very smooth red-brown bark. (It's used a lot for perches in quality bird cages).