Keep working on ZBrush. More and more of our big clients (think EA, Ubi, etc) are moving towards more ZBrush in their env art asset creation pipeline. The goal is: more baked details - Zbrush offers often better quality than just doing it in crazybump, plus it's often faster than hi-poly modelling everything.
The strength of Zbrush for env texturing though, is doing art styles and custom layouts that you can't get with photos. It might help to think of it as being just like painting a texture in Photoshop. Start rough, refine, until you get the result you want. The only difference is you're generating a 3d texture. You can use…