That said I think the surface at large (and close to the airfield) looks a slight bit to rough and not arid enough (i.e. with a slightly brighter "base" color and patches of bright and flat sand here and there).
Well, there photo-texturing has an edge... The terrain is classified as shrubland, and it has to work pretty much everywhere in the Southwest, so we have to compromise. We could get much closer to the terrain around KNID, but we'd screw up elsewhere. You can use the dust shader effect to adjust aridness locally though.
I kind of also miss the more-brown-than-green spotted pattern of round bushes that are common in US dessert areas like these (though that pattern "dissapears" at higher altitude).
They're there (although perhaps a bit too much on the green side(, and they disappear at higher altitude to avoid flickering Moire patterns)
I'll post a few close-up shots later.