I’m on adaptive 1/4 settings. Of course, if i go to 1/24 its get better. But the whole idea of the Hgloss was to “fake” specular, so it’s seems a bit strange to push all the settings.
Hgloss is not to fake spec, it is the specular component. It still needs light subdivs as far as I know.
If you want your images samples as low as 1/4 make your MSR 256. On your example this will render it very quick, about a second for me.
Just remember that MSR and image samples will need to vary depending on what your scene is like.
only disadvantage of putting a high MSR value, is that on complex scenes with lot’s of materials and reflections, it will boost all the samples on the image, and therefore rendering time will be much higher.
usually on my scenes a MSR value of 16 is quite enough
You may also resolve the noise via Image Sampler settings or via Light Subdivions(Use Local Subdivs must be turned on) or by combining all three of them: