I am guilty of over thinking these sometimes. If you allow yourself to, you can talk yourself up or down + or - a grade almost always and that's the trap of extra time () In the real world when I'm grading comics for the local comic book clubs, you don't have the luxury of that kind of time. The owner of the book nervously looking on, 5 minutes can seem like an eternity! But I like to think I can deliver a fairly accurate grade in about 5 minutes or so. Of course having the book in hand makes all the difference in the world!