What are the differences between older and newer editions of Hogg?

I don't wish for specific information, as I have yet to read the book, but does anyone know to what extent the editions differ? Is the more recent edition, like that of "The Mad Man", substantially expanded, or are the differences predominantly typographical? I currently have only the blue & black 1996 paperback from FC2/Black Ice Books, but if the 2004 is expanded, I'd prefer to have that one before reading. Thank you to anyone who may know.