CSG* (i guess tomato tomoto but really its csg with bsp) and They are generally right, static meshes are faster than csg per triangle.
however with the benefits of what i said, true dynamic lighting is a huge possibility with csg, imo.
There is no one fits all tool. If there were we would be using it. A combination of CSG and static meshes is the best way to ensure a properly optimized scene.