However, one type I've found often contains nothing useful at all. It's a book that assures you that there are N many plots or X many character types, and here they are. Partly that the types are (obviously) heavily abstract, so there's no real value in them. They never have useful ideas about to figure out which characters are which, or how to use that fact.
I have, however, heard from a writer who did find a use for them. That was, check her characters against them and see if she could match them up. If so, she worked on the character development more.