It is very strong, rough, tar-smelling, incredibly smoky. Described as "smoky birch tar burnt grilled leather" in The Good Scents database. I have not been able to discern the leather nuance.
A few decades ago a "tar shampoo" was very popular in my country. It was supposed to give you a shiny healthy thick hair. It always comes to my mind after smelling crude cade. Someone else said smoked bacon, when you overcook it.
Rectified cade is, basically, crude cade stripped of polynuclear aromatic hydrocarbons, which make it safer and IFRA-compliant, but also blander and more civilised.
BTW, crude cade is prohibited by IFRA for any commercial application: http://www.ifraorg.org/view_document.aspx?docId=22005