So I was going to make some images to illustrate what some of the values in Vray's Fast SSS2 and Fog Bias settings do but apparently I deleted the files. So the following images will not be as useful as I once intended them to be. The figure is about 6 inches tall and the cube is 1 cm x 1 cm.
Fast SSS2 - Refractive - Changing Scatter Radius Value and using Fog color
FastSSS2 - Solid - Changing Scatter Radius
FastSSS2 - Solid - Changing Phase Function
Sorry about the lack of everything. I'll try to do this again with all of the detail.