what does glossiness reflection and glossiness refraction control do to Brazil Glass Material?
I have been experimenting with changes in these paramters, but the results are so subtle that its hard to tell what the effect is.
It blurs them, higher number the sharper. If you have glossy reflections and refractions there should be a noticeable difference at least in toggling them off and on.
Not just talking about glass, glossy reflections of realistic light sources(an HDR and/or actual bright objects) are the much more realistic(and slower) alternative to all those settings about specular highlights.