This asset has been blocked out in Maya, sculpted in ZBrush, retopology and UVed in Maya and textured with both 3D Coat and Photoshop.
As all my other textures the Photoshop file is pretty modular (through the use of Masks and Adjustment Layers) allowing me to easily change and adjust many different properties of the textures: Albedo, Normal and SRM (Specular, Roughness and Metallic channel packed texture).
I usually pack and export my textures in Photoshop taking advantage of the amazing "Expresso" exporter: https://minifloppy.it/portfolio/expresso/
Marmoset Viewer - Table