I'm having trouble with noise. Its mostly in dark sections, it doesen't look to bad in the picture but that's with 3000 path tracing samples. It's rendering at 1920x1080 and using filmic blender at medium high contrast.
I guess the standard advice of making mesh light sources brighter and spot lamp sizes larger applies here, these would be the most "natural" ways of reducing noise.
If the Starmap is emitting light as an HDR, it might be a good idea to try Multiple Importance Sampling in Cycles.
But I do agree with you that one should expect a less noisy image at 3000 samples. Filmic blender actually doesn't affect Cycles contrary to popular belief.
Also, have a look at airenderer.com. It's a renderer that takes a noisy image (probably 200 samples is enough here) and gives you a more rendered result. It doesn't every type of scene well, but this looks like the type of scene this was built for.