Sorry, for not replying for so long.
That's exactly what I was referring to @nkilar.
I agree, this kind of attention to materials is needed only for closeups imo. In wider archviz shots I wouldn't go as deep.
What I found very useful though is using fresnel maps for both, IOR and Glosiness slots. With GGX you get pretty close to results from the posted tutorial from Grant Warwick. But the material stays very simple to modify as well. Which I think is essential.
I'm not acquainted with "tail falloff" in 3dsmax. But I use frensel in a filter which I can control with a curve. It works great.