I recommend getting both. In fact, I am using Gile[s] to create shadow maps for staticmeshes, which are displayed in CShop, and then CShop calculates the whole map lighting.
I am probably adding radiosity rendering in CS5, but Giles is the best thing for lighting individual meshes and arbitrary geometry. CShop is better for lots of large geometry, if you build the map in it.
I am probably adding radiosity rendering in CS5, but Giles is the best thing for lighting individual meshes and arbitrary geometry. CShop is better for lots of large geometry, if you build the map in it.