Hello,
Making tons of shaders per day, I thought maybe it’s a good idea to set the default Specular value to something like 0.2 which is where most non-metallic surfaces fall instead of 0.5 which is not a common value for either non-metallic nor metallic.
And most people skip to modify the Specular value at all thinking it doesn’t make a noticeable different and thus their reflection values are always far from anything close to accurate.