I’ve noticed that my scene look better with stationary lights than static lights, especially concerning metals. I found this on answerhub. I wonder if it’s still the case today in 2016 tho…
Static vs stationary specularity Static lights lose colored specular on metallic materials, stationary lights work fine - Rendering - Unreal Engine Forums
*This is a known limitation to the use of physical-based materials. The Static Lights are diffuse based only and will not take or contribute to a specular element like the Metallic and Roughness inputs. It is not on the roadmap currently to add an additional specular component to the static lights in the foreseeable future.
Thank You
Eric Ketchum*