the obvious answer is to read both manuals...

veils has variable lin/exp, offset (I believe, new version I only have the original) and a lot of gain (which can be useful - definitely enough for line-> modular) and sliders - off the top of my head

no idea about vincursal

"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia

Utility modules are the dull polish that makes the shiny modules actually shine!!!

sound sources < sound modifiers < modulation sources < utilities