Without actually knowing, Id say use the old one...which is what I use as a body shop specializing in Corvettes. I havent see a new one, but general rule of thumb for me has ALWAYS been new/improved means junk. I cant remember ever trying something new or improved that I thought was. Government regs usually manage to screw something good up everytime from glue to tvs.
If you really need info, contact Evercoat or look at their website.